[some-guy]

I haven't read much into it, but The Simpsons to me became terrible around the same time Family Guy came out. I don't know if trying to be like Family Guy made the show worse, or if the type of humor The Simpsons championed for so long became unfashionable.

A lot of people say Family Guy copied the Simpsons, but in reality I actually found that the Simpsons tried to copy Family Guy's style of humor and did a very terrible job at it.

[MPSimmons]

There's probably a term of art for it, but that Family Guy style cut to some previous reference hadn't really been done before, certainly not to the extent that Seth McFarlane did it. Simpsons copied it, but it never felt good when they did.

If you watch The Simpsons DVD commentary on the very first season DVDs, they talk about how Matt Groening's team would draw the key frames and then they would ship them to an asian animation studio to provide the animation frames. The very first time they did this, they got an animation style that was all over the place - not just the quality of drawing, but the actual animation style was jello-y and way more wobbly than they wanted. You can see it on YouTube here: https://www.youtube.com/watch?v=sx-wjF5AMmk

The main reason that they sent it back was that the style and physics represented in the cartoon wasn't the one they were going for, and it changed how the show felt. I feel like the rapid cut references they adopted from Family Guy did a very similar thing. It changed the flow of the show, which, maybe (?) is actually more of a sign of the times and attention span than animated show style, but still, I wasn't a fan and I didn't feel like The Simpsons did it naturally or that it fit, and it takes me out of the narrative every time they do it.

[dfxm12]

There seems to have been a big turnover of writers in 98-99. As in very few people who were there in the beginning were left by that point. You're not considering that the original charm of the show was lost with the original creative force.

Family guy debuted in 1999. It's hard to say Simpsons tried to copy family guy's style. Family Guy is really known for its cutaways (usually to some non sequitur) & somewhat crude humor. A lot of the jokes at this time hinged on Stewie not being understood by anyone but Brian, Brian himself being a dog. There were also a lot of references to musical theater. The Simpsons was different from this.

[bubblewand]

The Zombie Simpsons explanation paints it (fairly convincingly) as a combo of deaths, turnover in the writing room, and the influence of The Simpsons and other “subversive” shows affecting the mainstream so much that it was no longer distinctive, with the result that the show became a heightened, silly, absurd, but basically straight, and (more, at least) earnest, version of the family sitcom it had started off lampooning.

https://deadhomersociety.wordpress.com/zombiesimpsons/

Under this explanation, the early show is basically a totally different thing from what it became by somewhere around season 10. Even if it didn’t “get worse” (I think it definitely did also do that, but it’s not necessary for this explanation to work) it became something so different that it’s not surprising that a lot of people who liked the early show, don’t like what it has been since the change.

[jamesfinlayson]

I remember reading years ago that in the early days the executive producer had a two year tenure, then from season 8 or 9 it's been the same guy with no change.