Really tried to understand your reasoning here but it seems to be as simple as There Has To Be Some Reason for the excessive injuries.
You speculated that it was McVay. Then Management. Now it has to be "Something changed'. No facts or specifics but it's got to be something is different or has changed. That sounds a little like a Conspiracy Theory.
I see the Rams' 2022 failure as being primarily the result of an extreme number of injuries, especially to the unit (O-Line) that most needs continuity. No 'Head in the sand' here. Just the way things go sometimes when a team is decimated by injuries.
Even gave a couple of specific examples; and pointed out that the teams I mentioned (Niners, Ravens and Rams) all had the same head coaches and front offices through the up/down seasons. Those teams went from very good to quickly being bad (due to excessive injuries) and, then, back to being good in the case of the Niners and Ravens.