I actually agree with you here that Vasy is in a different category, mainly because he performs so much better than anyone else Tampa has thrown in the net over the last few years that's it's a markedly noticeable difference. What the Islanders have done is consistently dress above-average goaltending to go along with their solid D. Lehner was a Vezina finalist 3 years ago, Griess just left the team as having one of the highest save% in Islander goalies history and Varlamov came 5th in Vezina voting this year. With Sorokin looking like another ace pickup, I think their goaltending department deserves some praise. It's not just their good D.
Your defense of Freddy is admirable but I push back that Andersen was once a much better goalie. Along with the injection of the high powered young core, he was the reason for the Leafs early success in the Matthews era. From 2016 to the end of the 2019 season, the Leafs enjoyed the 5th best team save% in the league. This wasnt due to their team defensive structure I assure you. They were bottom 5 in almost every way we track team D. The problem was that a massive workhorse like Andersen can't keep that up forever once Freddy started to slip and inconsistency crept more and more into his game, it was offset by the growth of the young players and when the start of the 2019 season came around things really went downhill for Freddy. He was still capable of going on a run but shots started going right through him and he seemed slow to react. It's like the play you are referencing. If he quickly recognizes the situation and collects the puck behind the net, theres no chance....or if that useless plug Marincin (who replaced the Leafs best playoff D in Muzzin who went down with injury) just pressures the guy, nothing happens as well as the changing players would have had opposing players covered. Or Andersen could have just hugged the post properly as Marincin was picking daisies in front of the net covering anyways. Lots of things went wrong on that play but I wouldnt put it down as a classic example of anything.
Why do you think Babcock got fired? It's because that run and gun system doesn't work so well when team goaltending falls from top 5 to below average. Once Keefe came on board, team D trended towards the top 10 and made up for the slippage in net and the Leafs have actually given Andersen all the rope in the world the last year and a half really. Yet here are the stats with the Leafs since Keefe was hired:
Campbell:
GP: 28
Save%: .920
Hutchinson:
GP: 17
Save%: .905
Andersen:
GP: 59
Save%: .903
The Leafs have been plagued by injuries for much of Keefe's tenure (including to Andersen himself) that may be affecting these numbers but it doesnt look good. Big gamble by the Canes to throw that money and term on a guy north of 30 trending in that direction.
I dunno, maybe it's the level of importance that goaltending takes in the game that makes it so mysterious then. I actually think the Leafs are looking at the Islanders successful tandem system when they picked up Mrazek, a guy like Campbell who plays well but wears down with too big a load.
When looking at team D numbers since Keefe came on board, the Leafs and Isles match up well defensively. Having another .920 keeper on the roster instead of what Andersen brought over that time will do wonders as well as give Keefe a confident option coming off the bench in the playoffs.
Fewest shots against ranking since Keefe was hired (league wide):
Toronto: 10th in the NHL
NYI: 11th in the NHL
Fewest High Danger Chances Against ranking since Keefe was hired (league wide):
Toronto: 8th in the NHL
NYI: 13th in the NHL
Fewest Expected Goals Against ranking since Keefe was hired (league wide):
Toronto: 5th in the NHL
NYI: 9th in the NHL
These number's are skewed by the strange covid year of course but I'm very interested to see how things play out.