I watched both Bears games, and aside from not telling his kicker to kick the ball out of bounds (which he should have done), the losses were certainly not on Ben Johnson.
1) Caleb Williams just isnt that good yet (if he ever will be).
2) The Bears roster is rough at several positions.
So you speaking of the nice situation he had in Detroit is ironic, because if we are having this conversation in the context of what he could have done in Buffalo, it would be wise to mention that he would have had an equally rich situation in Buffalo as he did in Detroit, thanks to Josh Allen (who is worth about 5x what Goff is) and James Cook.
That being said, I never wanted McDermott fired ,so its a moot point. But your argument doesnt hold water.