The top: cartoon styles over at least seven decades. The bottom: a handful of cartoons from maybe ten years or so. Popular styles change. Look at the old Hanna Barbera cartoons. Yogi Bear, George Jetson, and Fred Flintstone all have the same template because that style was popular with a certain studio at a certain time. And this post ignores cartoons like Phineas and Ferb, Adventure Time, and Regular show, which all have their own unique styles different from the ones pictured below.
I know, right? I wrote a long ass comment on a similar post that said that old cartoons are better. The comment was about how today's cartoons like Avatar, Gravity Falls, Adventure Time etc. have much deeper plots, better written characters and less copy-paste slapstick and how the OP is just nostalgic. It was really long and ffs I don't wanna type it out or try to find it and paste it here because I've done it a thousand times already. So I'm just gonna agree with you. Some people are just stuck in the 90's.
No no, what I meant (and I'm sure that sero meant the same) was that people who were kids in the 90's (aka people born in the mid-late 80's/early 90's) watched these cartoons. The fact that the cartoons themselves are older is irrelevant, what I meant was that they were aired in the 90's (some after many repetitions from the earlier years). And now 90's kids won't shut up about them.
Not to mention thanks to time, the worst shows from back then have been all but forgotten. While we still have to deal with the trial and error of what might be good today.
You know what, once someone stuck in the 90's, they ain't coming out.