Benching Josh Allen is throwing in the towel on him. I won't be fine with the team doing that unless they are pretty sure Josh Allen can't be that guy.
The good news is he has 2 wins as a rookie QB on a low budget team that had a piss poor offence before he arrived.
Just to entertain your hypothetical, this new QB whoever he is probably isn't some game changer to put your hopes on. He would struggle as well.