Directors Joe and Anthony Russo have debunked an ‘Avengers: Endgame’ theory that was seemingly confirmed by the film's own writers previously. The point of contention is whether or not Steve Rogers created an alternate reality when he travelled back in time to restore the ‘Infinity Stones’.
In ‘Avengers: Endgame’, the superheroes attempt to reverse the effects of the villainous Thanos' snap, which they do by collecting all the Infinity Stones by travelling to pivotal moments from the past. At the end of the film, Steve Rogers offers to go back into the past to restore the stones. In doing so, he lives out a happy life with Peggy Carter, returning to the main timeline only as an adult.
In an appearance on the Lights Camera Barstool podcast, Joe Russo said, "Based on everything that happened, he would have been in a branch reality and then had to have shifted over to this, so jumped from one to the other and handed the shield off… One thing that's clear that Anthony and I have discussed, I don't know that we've discussed this publicly at all, Cap would have had to have traveled back to the main timeline.
That's something that, yes, he would have been in a branch reality, but he would have to travel back to the main timeline to give that shield to Sam Wilson." —Flickprime
