Their success and failure seems entirely contingent on when they have a fully healthy OL or not. They can sustain an injury to Feliciano or Boettger but not both, and they can not sustain an injury to or absence of Spencer Brown. With Taylor, they also really needed Edmunds and Lotulelei and both were out as those two guys are the biggest reason Buffalo is so good against the run.
I'm not making excuses. The depth is poor. Baltimore are frauds but they still squeak out wins with a bunch of injuries. The Bills don't have that kind of depth, and if 100% health is required to be a great team, then it kinda sounds like you don't have a great team. On top of that, they have been incredibly undisciplined. So many 3rd down stops this year have been negated by stupid penalties.
Every team in the AFC is weird. I think the Bills at their best are better than any other AFC team at their best, but every single contender in the AFC has been blown out at least once. The Titans, the #1 seed, have 3 losses: 2 of which are to the Jets and Texans. This year makes no sense.
On top of that, the Bills piling on wins against WFT, NYJ and HOU while falling to every playoff team outside the Chiefs + the Jags loss is not a good look at all.