2) The Mets bullpen isn’t deep
How many Mets relievers do we really trust? Edwin Diaz can enter the circle. So can Jose Butto. Guys like Reed Garrett and Phil Maton are up for debate. Chances are you only have enough trust in your heart for one of them at the maximum. Everyone else is a lot more unreliable.
If the Mets make the playoffs, their postseason roster might include a bullpen featuring several starters instead of relievers. Tylor Megill has pitched much better than many of their relievers. For nothing more than to eat innings, he should be under consideration.
Playoff rosters do shrink by two and the Mets don’t have any hard debates to have in terms of leaving someone out. Eddy Alvarez who is ineligible for the playoffs altogether won’t join them. As for the pitcher, it’s up to them to decide if they hold off a starter for the next round (go ahead and laugh) or a reliever who hasn’t shown he deserves a spot. Is there any situation where you'd trust Danny Young or Adam Ottavino?
One can argue a deep bullpen is better than a top-heavy one. The Mets don’t have either. Not every day can be starter to Butto for two or three innings and then Diaz. Others will have to fill in. This can absolutely destroy this team.