Like any other entertainment medium, animation has greatly evolved from its humble beginnings, in both the art itself and how it is presented. From the rise of golden age cartoons, to providing full feature-length experiences; from delivering artistic, abstract experiences to going full primetime sitcom; from inception of television, to the ongoing move toward streaming - it's a neverending chain of advancements and developments. Of course, it helps that evolving technologies allow for progressively more flexible formats on top of that. There were more limitations in the earlier years in how they were able to make the moving drawings come to life, and fewer opportunities to indulge yourself in the medium. But now, you can watch your favorite shows and films on practically any screen you can, and with animation's barrier of entry getting gradually lower, it's now more important than ever to create experiences that the customers will want to stick with and come back for more.
And one of the most interesting evolutions was when cartoons deviated from the episodic, self-contained standards, generally done for both ease of rerunning and also naturally carrying on from the gag-heavy nature of the medium's big pioneers. Continuity had been around in animation since at least "The Flintstones", or debatably the multi-episode arcs of "Rocky & Bullwinkle", but it only took around the 90s for them to full-on embrace serialization with a select few programs like "Sonic the Hedgehog SatAM" and "Gargoyles", which were both highly praised but were ultimately cancelled before their prime (some things never do change). It helped that it was around this time when anime, particularly the likes of "Sailor Moon", started to reach American airwaves. Thus, the many different styles and tropes unique to that country's work were exposed across the pond, the influence of which would quickly carry over into the 2000s with "Samurai Jack", "Teen Titans", and of course, "Avatar: The Last Airbender".
Now, with western animation, there's a few big innovators that people generally push as the contributors to the current boom of serialization. "Avatar: TLA" was the perfect storm of talented artists, writers with a defined vision, and the network putting enough trust to let it all come to life as intended with little compromise. It truly felt like an anime made by western artists, and a dang impressive one at that. While far from the first show to have this feel, it was among the first to be fully realized, and it forever impacted how animation was approached by many. There was more of a widespread respect for it compared to earlier, and this would only continue to rise in the years following with the reality show spoof "Total Drama Island" and the adventure fantasy "Adventure Time" becoming heavy successes themselves. But the real game-changers on this front are often said to be "Gravity Falls" and "Steven Universe", being so tightly-connected in their stories, and pushing the boundaries on what content that can be exposed to 7-12 kids. These allowed more and more cartoons of this nature to arise, and in various different forms at that.
Not to say episodic cartoons have disappeared, quite the opposite in fact. One of the more traditional setups still proudly used today are the family sitcoms, with shows like "Big City Greens", "The Loud House", and - on the adult side of things - "Bob's Burgers" and "Duncanville" currently carrying the mantle. They vary in how grounded in reality they are, but are all ultimately about the family's dynamics and the adventures they share. There's also screwball comedies built on absurdism, particularly popular with throwbacks that include "Looney Tunes Cartoons" and "The Wonderful World of Mickey Mouse", but also a number of particular staples including "Teen Titans Go!" and "Spongebob Squarepants". And, in the middle of those, is the slice-of-life variety ranging from your grounded "Craig of the Creek"s, to the fantastical but energetic "Ghost and Molly McGee"s, and - particularly prominent with the preschool audiences - simple, careful, sometimes adventurous days spent with a likable group, as is expertly presented in "Bluey". Note that even when grouping like this, each show mentioned is incredibly distinct from one another.
However, anyone who hangs around cartoon discussions alongside will notice a severe lean toward the serialized and lore-heavy shows when talking about what's current. Part of it is because, by default, there's more information to chew on and absorb in the long run, as well as greater investment in stories that are given more buildup and time. But even with that in mind, it felt like most episodic cartoons debuting between 2016 and 2020 was getting outright ignored online. You had a hard time finding anyone who decided to check out "Summer Camp Island" or "The Fungies", and even some with a prominent name attached like 2019's "DC Superhero Girls" struggled to catch on. And while things have majorly improved since, with programs like "Jellystone" and the 2020 "Animaniacs" reboot getting heavy positive attention, you still see a bias in places, which came to a head recently when "The Ghost and Molly McGee" premiered and many actively insisted it get more dramatic down the line and that it's a 'standard kid show' as it currently stands, much to the annoyance of those who already became attached to the new series.
I'll admit, this trend got under my skin for the longest time. I always believed the quality of something is the sum of its parts, serialization simply being one of many elements, and like any other storytelling technique can and has been horribly botched. Yet so often, I saw many crowds believe serialization and lore are, in and of themselves, the main determinants of a new show's quality or at least how worthy it is for us to look at. This mentality made me particularly dislike it when shows started in a more unique direction but over time blended in more and more with this bandwagon (see "Star vs. the Forces of Evil"). Obviously, even then there were many serialized cartoons I was both excited for and ultimately really enjoyed, like "Infinity Train" and "Amphibia", but I always made a point to say it was for many different elements within the show than just the one. It was never about just the fact they were story-driven, it was always how such a technique was approached and executed. It has to grab me in with the premise first, and if it lends itself well to being told as an overarching narrative, so be it; if not, I'd prefer the self-contained approach.
But I think one of the biggest factors in why fans prop up the emotional, dark, and story-driven cartoons above the rest is because of the struggles they often face in the animation business. Networks are often concerned about a show's ability to be rerun and for any newcomer catching a random airing to not feel lost, a philosophy known as 'continuity lockout'. This is why Avatar began episodes with a montage of all the events relevant to what's about to happen. In addition, if they commit to directions the network may not approve of, or just management shifts screwing up the relationship; many compromises must be made in these artists letting their stories reach their full potential, sometimes not even getting a concrete ending. It's clear a lot of the time, channels are plain reluctant to really allow serialization because despite their online success, they tend to go against the kind of programming that prove more commercially successful. All these factors combined are what led to "Infinity Train"'s premature cancellation.
This has only gotten more complicated with the shift from cable to streaming services. As more hardcore viewers, teens, and millennials alike are cutting the cord in favor of internet-based alternatives, most of the remaining audience on cable generally consists of younger kids. Meanwhile, Nick has Paramount+, Cartoon Network and Warner Bros have HBO Max, and Disney Channel has Disney+; so any new continuity-heavy series made under any of these production companies are naturally going to be considered better fits for streaming rather than the more obsolete alternatives. This has become especially obvious with the latter, who has explicitly announced plans to target Disney Channel toward 7-12 kids with Disney+ aiming for more general audiences, hence shows like "Amphibia" and "The Owl House" (which continue playing on the network due to contractual obligations) becoming phased out from the channel in favor of more lighthearted programs like "Big City Greens" and "The Ghost and Molly McGee" - and, of course, TOH suffered as a result.
However, I strongly believe this rough transition and uphill battle shouldn't overshadow the need for variety in the media we consume. Apart from the simple fact that nothing will appeal to everyone, sometimes we just find ourselves in a mood to watch something we don't have to think much about. This doesn't make the shows any lesser of an experience, they're just a different one that can be of equal - and possibly higher - value. It's not like simple cartoon hijinx can be considered obsolete either; with the ever-changing trends and technologies encompassing society, there are always new opportunities for gags, heart, and experimentation. Something like "The Wonderful World of Mickey Mouse", being as unhinged as possible while taking full advantage of the medium's current strengths, does this fantastically and is almost unanimously adored for it. If Molly McGee really opted for a more "Owl House"-like approach (or even vice versa), then it would just feel too familiar and make both shows' appeals feel more segmented. The fact they both have different goals and greatly succeed on those fronts is something that should be applauded.
Frankly, the idea that cartoons should be grouped solely based on its structure and continuity is looking more ridiculous the more the animation landscape varies itself up. Cartoons are made up of many varying style, ideas, personalities, techniques, and so forth. Each direction should be approached with nuance instead of being placed in a bubble like they generally are. The more unique a blend, the more special and recognized it will be in the long run; see just how beloved the incredibly upbeat and action-packed "OK KO: Let's Be Heroes" and the mature, surreal "Regular Show" are to this day, compared to something like the middle seasons of "Adventure Time" which many agree became too self-indulgent for its own good. Same goes for analysis; "Steven Universe" has way more in common with "Craig of the Creek" than either "Infinity Train" or "The Owl House", yet its fanbase has vastly more of an overlap with the latter two because of their serialized, dramatic nature and, in TOH's case, LGBT+ representation - and it's tiring to see constant, loose comparisons tossed around that do nothing but spawn petty discourse.
However, even when comparing two serialized or episodic cartoons together, I think it's very important to respect what they each represent and offer, while also understanding the appeal of more lighthearted stuff. We all have tropes we prefer, sure, but respect that everything is the sum of its parts. Overall, content should be watched and supported based off how it comes out as a whole rather than the mere existence of a singular technique that may not necessarily end well anyway. It's fine to prefer programs that do one or the other, but try not to look down on the so-called 'opposing' side of the landscape or consider any show that happens to take the other approach not worth your attention by default. You never know when you'd end up missing out on something incredible to remember for life. They are all cartoons, after all.