Full spoilers ahead for Avengers: Endgame!
The consequences of using the Infinity Gauntlet in Avengers: Endgame are already being depicted on the big screen, as the new trailer for Spider-Man: Far From Home revealed that the Snap damaged the fabric of reality enough to expose the existence of a multiverse.
Source: IGN.com Endgame Writers Unaware of Spider-Man Multiverse Plans