What we do know is what McVay has said so I will stay in that lane.
Sean accepts responsibility for not putting his players in the best situations all the time. He directly laments specific play calls he terms "stupid." I believe we can all agree that plays break down for a myriad of reasons that the staff reviews after each game. Self scouting is integral to the structure of how they operate. They know who missed their assignments in blocking, route running, and passing.
What McVay has also alluded a few times was that there were specific solutions to what the defenses did but those solutions were not executed by the QB. The fact that they were willing to pay extra to trade Goff for Stafford is all the evidence we need to see that McVay had difficulty getting Goff to process that information to McVay's standards. This doesn't mean that Goff failed to do so all the time as there were hundreds of examples where the plays worked and Goff performed well. It's the number of times that didn't work that has driven the team to this decision to take another direction at great cost.
With that said, the rest of the offseason moves on offense SHOULD indicate which players besides Goff were the most responsible for operational failures. While McVay praised Blythe's decision-making, he didn't comment on his physical ability to execute the position. We don't know which players grade poorer than others in their system so we tend to speculate based on what we can each individually see and understand. The truth with this regime is that they publicly praise players out of respect but replace them when they don't perform to the expectations communicated to them. Sometimes, they replace players due to salary cap management. All this should be obvious but I state these things here because it doesn't seem to be obvious based on some of the posts I read.
