Maybe I'm just a Keefe apologist but when I look at all three of these series I just look at a few things:
Columbus series was all on bad goaltending IMO
Montreal series was all on the Matthews/Marner/Hyman line, only 2 goals between them the entire series sunk us.
The Tampa series is another one, I don't know what I would have changed other than an extra save from Campbell and the officiating not being total trash. All the big guns came through IMO.
I do 100% agree though that it's a results based business but I haven't left any series thinking Keefe was the reason we lost. Game 5 vs the Jackets is probably his biggest coaching blunder in that stretch, but that entire series was dumb considering the pandemic etc.
We'll have to wait and see again I guess.