It seems to me the problem was the stereotyping. Initially from a 1 dimensional cliché he evolved into a still problematic 2D character, though they added a family, etc. It actually seems like an easy fix to keep adding more authentic details to flesh his character out further. We know Ned lives next door - but who lives on the other side, behind them, across the street? Maybe Abu could move nearby, share some hobbies and interests that weren't just tropes.

It wouldn't be impossible to resurrect the Simpsons with fresh ideas and good writers and maybe some structural experts and script doctors. It would be far easier to refurbish The Simpsons than to try to develop a new hit series ground up. While it's been a long slow slide (I can't remember the last time I saw one) it's got solid foundations and a sturdy frame.

Sadly, Disney now owns Fox, and we've seen what they do to strong franchises. I suspect they'll milk it until it's dead, and maybe even after.