At 27 yo McAvoy should be entering his prime but fundamentally he has been grossly mismanaged in the last 4.5 seasons and his game has regressed each year.
With Krug's and Chara's departure in 2020, all special units were given to him on a silver platter.
At 22 yo McAvoy still needed a role model to work on his game and polish it. Instead he got a Krejci treatment of a revolving door with Lauzon, Reilly, Zboril and Grzelcyk, none of them a top pair Dman.
Eventually Grzelcyk was the one to stick with him. Next to him, McAvoy looked like a dominant Dman since Grzelcyk could not play physical, had no slap shot, a weak wrist shot, no gap control, short reach, his only above average skill was skating and edge work.
The standard was drastically lowered. There was no one to challange him. During the regular season the pair was good enough against mediocre and lottery pick teams. However, as soon as the playoffs started, they got exposed and were just rubbish.
McAvoy's Playoffs production since 2020:
2021 1G 11A in 11 games
2022 0G 5A in 6 games
2023 0G 5A in 7 games
2024 1G 5A in 13 games