I agree, and admit that what I'm about to write is all based on hindsight that could not have been foreseen, but...
First, after a terrible start and 3 points from the first 6 games, NYCFC really did start playing significantly better, but this was masked for a time by poor conversion of scoring chances, even while at full strength. Yet for all the obstacles:
- when Maxi missed 7 straight games, the team earned 1.57 PPG
- after Heber was injured, the team earned 2.30 PPG
- even after Mitrita left two games later, the team earned 2.00 PPG
With even one extra piece, especially a true striker to complement/backup Heber, this was a potential juggernaut of a team.
Second, every other team had weird crap to deal with this year. Toronto had a bunch of injuries, and after they stopped playing every game against Montreal or Vancouver, no home games; Atlanta's perennial MVP candidate missed the entire season and they fired their coach; Miami only started to click after getting their 3rd DP deep into the season and then 3 players got Covid just before their first historic playoff game; the Red Bulls were in 100% rebuild mode and also fired their coach, but things started to gel (6 losses in the first 12 games, 3 losses in the last 11) and with the right new 1-2 pieces could be a much bigger challenge in 2021. Next year the MLS East will not be any easier for NYCFC.
Third, NY sports has been pretty bad for a while but 2020 has been epically and singularly bad, and a run to MLS Cup -- even just making the finals -- after every other local team completely failed and while there is no theater, limited new TV content and no movie openings and the election season is behind us and we may be entering a new near-lockdown and a lonely dismal holiday season with limited to no travel -- had a unique opportunity to get noticed in a way that I both hope and expect cannot happen again. I'm not saying NYCFC jumps into parity even with the local NHL teams (though maybe with Devils and Isles at least?), but this year certainly could have provided a bigger boost than your average year.
Like I said, this is based on a lot of things that could not have been predicted. But success rarely comes to those who devise reasons not to be bold.