I think part of this is because of the Cartoon Violence Effect: Violent things happening to cartoon characters are funny in a way that they wouldn’t be if we saw them happening to real live people. The fact that it’s a cartoon provides an extra layer of distance between the viewers and the characters that actually helps with certain kinds of comedy.
The Critic, with voices by Jon Lovitz and others, was also canned. Too bad - it had its moments of brilliance.
The three Simpson kids have had about six birthdays between them, by my count, but they always remain 10, 8 and pre-1.
But Homer has aged. IIRC he started out age 34 but is now 39, or something. Although that was more by fiat than any sort of natural progression.
Right, he was 36 and is now 39. They even called him 40 last year, sorta. But yeah- different deal.