The pandemic likely helped the Islanders more than some other teams, yes.
You're using a team statistic and attributing it to one player. That's nonsense.
The Islanders missed the playoffs because the roster wasn't good and the coaching was awful. We had Ladd, Hickey, Chimera, Quine, Prince, and Gionta on the roster in 2016-17. Beauvillier was a rookie, Hamonic got hurt, Strome was a 30 point player, we had Berube start in 14 games. We had f***ing Connor Jones play as a center in 4 games, who the heck is that?
In 2017-18 Boychuk only played 58 games, Cizikas only 64, de Haan 33, Tanner Fritz played 34 games, Sebastian Aho played 22 games, Alan Quine played 21 games, Brandon Davidson played in 15 games, Christpher Gibson played in 8 games, Chimera regressed.
We never had an established third line during that time, our defense was not good and featured Hickey in the top 4 both years. The coaching was abysmal in both seasons. Capuano would have a November slide every damn year and didn't understand how to coach in the NHL. Do you see him as a head coach somewhere in the NHL right now? Nope. Doug Weight didn't have a clue what defense was at all and just let the guys run and gun for as long as they wanted. I mean, they had a historically bad season in terms of goals against and you're going to sit there and try to say Martin's departure was a big reason for that?
Why don't you start using some information other than team success and failures for evidence of how important Martin is?