You have some great points in your full post. I can't disagree that the Bills have prioritized DL.
I don't think it's supportable to say "above all else in every single year Beane has been here". I think the use of a 1st round pick to trade for Diggs, when it was clear we had a good 1-2 punch in Brown and Beasley already on the roster, argued a commitment to a quality WR corps. I mean, if Beane prioritized DL above all else, why not skip the Diggs trade and try to chase after a DLman there? Or go for a FA acquisition then and draft a WR, in what was a pretty rich draft? Beane wanted to give Allen a sure bet at a seasoned and crafty vet WR, and he did. I can't fault that.
And having the #2 offense, #3 passing offense that year and #3 offense, top-10 passing offense the following year makes it a bit revisionist to argue that what was on the field for the Bills in 2020 and 2021 showed that Beane hadn't done enough, offensively. I think after 13 seconds it looked to most of us like it was the defense that faltered - and hasn't that been a theme for most of us, throughout this season until the script flipped the last handful of games?
A friend of ours works professionally with wild animals. They like to say "it's always OK, until it isn't" - meaning unsafe things can be perceived as acceptable, "never had a problem", until one day they do.
I think where Beane went awry was after 2021, in assuming that Davis, Crowder, McKenzie, and a 5th round draft pick were adequate to replace Saunders (who replaced Brown for a year) and Beasley. They weren't, and they still aren't, although Shakir is looking as though he may have something now.
Kincaid may have been a good start, but he's got to do more.