I get that I'm late to this thought. "Everything Simpsons sucks since Season 9" is a 20+ year old refrain. But I have disagreed for years. I've enjoyed most-all of the episodes of every season before the movie. But since then, there has been a marked decline in my enjoyment, to the point that I just can't care anymore.

Maybe the fact that since the characters don't age, Homer's age lines up with the date. In the series he's gone from Boomer, to Gen X to Millennial. With the disparity in the living conditions of these groups, maybe it's time to let the show go.

Homer is canonically 39, so when  the show debuted in 1989, he was 'born' in 1950. But then he was an Alt Rock hero in "That 90s Episode" predating Nirvana, making him solidly Gen X. Now he'd be born in 1981, a cusp Millennial younger then me. 

The Simpsons makes sense as a show about a Boomer with Millennial kids (Bart is 8, making him "born" in 1981 in the debut). He has a good job with benefits, can afford to support his dad in a nursing home and his wife as a homemaker (already out of date in '89, but lets skip that). That framing makes no sense for the current times. it's out of touch with reality in such a fundamental way that Bart should be Homer now.