In a low-to-the ground format like Modern, Fatal Push can take down almost any creature on the battlefield with the consistent revolt triggers due to the Fetchland mana base
As such, it's better to wait to cast Maha until all the cards you need to start consistently wiping the board are in your possession.
Im going to make use of it in my Trostanis Angels deck, which commonly gets into triple- and quadruple-digit life totals
In a Limited environment where everyone is playing morph creatures and the average size of most creatures is about a 2/2 anyway, having a creature that morphs into a 3/4 without paying any mana whenever you feel like it ends up being a huge blowout
This is squandered potential, with the overall deck feeling like Jund Graveyard Stuff and a glimmer of inspirational design with the face commander and the theme it promotes
The Vintage players, the Cube drafters, the Commander players will all tell you, they want to have that super-rare card in their decks just for the moment when someone asks if a card is real in a hushed tone of voice