This is the most important stat so far: The Bills dominated two 1-2 teams. They were dominated by one of the six NFL 3-0 teams.
But here is the defensive stat to hang your hats on. The Bills have faced, Andrew Luck, Tom Brady and Ryan Tannehill, which is a cross section of QBs almost universally regarded as being in the top half of the league and two who are generally considered top 10, and one who maybe the GOAT. The Bills rank fifth in the league in defensive passer rating, holding the three teams they have faced to a rating of 78.1, fifth in the NFL so far this season. If the Bills offense is effective, teams are forced to put the ball in the air. Garbage time or not, that is an impressive stat.