Combo decks are a constant feature in both constructed and Commander, and wherever they thrive, Mai will be a great tech option against them
Sure getting the trample and haste when you first cast it is nice, but after that you're left with a vanilla 7/7 as your Commander, and that is just not going to get you there
If they block with a 5/5, they take 5 damage, and you can always run it with the Blasphemous Act / Star of Extinction combos
As the third mode is performed, first the player whose turn it is chooses two creatures they control, then each other player in turn order does the same, knowing the choices made before them
Fabled will also mark the first time the game will rotate cards out of being legally available to competitive players to include in their decks