Was it because he created a new branch in time, lived there for many years, and then somehow traveled back to the “Sacred Timeline”?
Or was it because he actually did not create a new branch in time? Steve in fact, spent decades of his life with Peggy within the Sacred Timeline, without leaving any witnesses or record or changing anything.
Likely because, in the time-line the Authority was protecting, he was supposed to do that; just like he was supposed to go back to claim the various infinity stones from different points in time.
shareThe TVA don’t care about time travel specifically. They just care if the sacred timeline is broken.
shareAccording to the time travel rules, that wouldn't be possible. There's no way he could have gone back in time and not changed something.
Either the TVA didn't deem that timeline worth pruning, or they weren't able to overpower Steve in time to prune it. My money is on the latter.
The prevailing theory among us "Steve was always there" proponents (that include this film's actual writers) is that he stayed out of history's way.
It's a tough pill to swallow, though, based on what we know of Steve. He's just not the type to stand by and let evil things happen to good people, no matter how much older and wiser he becomes.
But I just read a YouTube commenter's theory that I like a lot, a hybrid of both theories that finally reconciles Cap "always having been in this timeline" with Cap "never giving up the fight."
He's always been in the MCU since the 1950's, like Markus & McFeely intended, BUT he hasn't been standing idly by. He's been actively ENSURING THAT HISTORY PLAYS OUT AS IT SHOULD.
He was playing the long game, like a master tactician. He's not witnessing history but protecting it.
No wonder the TVA from "Loki" leaves him alone. He's doing their job for them.
I've heard that theory, but it makes no sense to me. When you consider all he risked to save Bucky, I can't seem him idly enjoying retirement knowing that Bucky is being experimented on, tortured, and used as a Soviet assassin for 70 years. Add to that all the terrorist strikes, assassinations, and natural disasters he knows are coming, and it's impossible to imagine him hiding from it all.
I understand that if he does something, then the timeline will split, and in some other universe Bucky will still be a captive, but I still don't see him accepting that. He simply isn't the type to hide for 75 years while so many awful things happen in the world around him.