McDermott is either A) involved in changing the offense to a worse, less effective offense, or B) he is not involved in the offense. It is one or the other.
If McD is involved in the offense (we know he wanted Allen to run less), and if McD had problems with how Daboll ran the offense, switching to Joe Brady (or anyone else) is unlikely to, or will not, resolve the problem.
If McD is not involved in the offense, then it is his failure as a coach to not be aware of the situation prior to the season starting. This is not his first rodeo. He's not a first year head coach.
Either way, the fragile hopes of the season now rest entirely either on Joe Brady or the Sean McDermott/Joe Brady brain trust. Based on past track record, if the offense succeeds, at the end of the season he will take credit. If the offense fails from here on out, he will blame Brady.
McD is the leader in charge, so at the end of the day it is his responsibility to right the ship. Ten games in, we look more like the 2018 Bills than the 2020-2021 Bills.
He still can’t manage a game. The team is still undisciplined. He can't manage his timeouts, his challenges, or his special teams. The team still doesn’t look ready for a most games. His QB looks depressed. He failed to address, at all, at any level, the issues his #1 WR was expressing last year, and in the offseason, and in training camp.