So based on your logic, he's arguably a top 5-10 dman in the NHL, which IMO, he's always been.
I personally ain't worried about his struggles as our entire team is a mess + he's playing with a turnover machine in Lohrei.
He's way too talented to not figure this out, especially with all the changes we've seen this offseason.
IMO, with the exception of Makar and Hedman, if you put McAvoy on any of those other teams, he'd have a lot more support to be a top 5 dman. Seider hasn't been that much better than him and Serg, Werenski etc don't have the overall game that McAvoy has.
Keep calm and move on