For what it's worth I think it took a long time for him to recover from the van accident which is why his writing was so wonky for most of the 2000s (it's probably his worst decade for output, though there are a few standout gems)
But even prior to the van accident a lot of his 90s work is a bit on the eh side as well, that could have had to do with recovering from drug and alcohol addiction and again, there's some real noteworthy exceptions.
He started off very strong in the 70s and 80s which is what made him such a legend, but then kind of coasted for a while while dealing with personal shit like the aforementioned addictions and van accident, eventually he recovered though and alongside a certain maturity as well simply doing it for so long really hit a new stride in output, I'm serious when I say that among the American pop cultural landscape of 2011-2022, as so many things went to shit, Stephen King's writing actually got better than what it was immediately prior, it's been fascinating to see and makes me glad he wasn't killed all the way back in 1999.
Though there is an issue with TDS, but the dude was always a very basic bitch Democrat from the start, so it's not too hard to overlook, remember all the shit with Greg Stillson in The Dead Zone? And I forgot to mention, as
@Dwight Frye mentioned, the strawmanning of pro-lifers in Insomnia is HILARIOUSLY overblown.