> "You’re backtracking. The thing you said, that I disagreed with was “the Avengers went back to an alternate timeline to get the stones, then went back to their own universe”. That’s just not true. Firstly, Infinity Stones from Alternate Universe don’t work in your Universe. So the IS’s from Earth-1 would NOT work in Earth-2. This was confirmed by Loki."
The MCU Infinity Stones are either fundamentally different, or alternate universes that are created through time travel happen to have different logic. Either way, Marvel considers those to be alternate timelines because otherwise events should have played out the exact same and those future Avengers should have always been there in those older films.
The TVA exists in the Null-Time Zone. Magic doesn't even work in the TVA apparently, so why would the Infinity Stones?
Additionally, the MCU is Earth-199999 and those alternate timelines are currently undesignated.
> "Secondly, all the IS’s that the Avengers collect during Endgame are quite clearly from the same Universe, just at an earlier point otherwise the Infinity Gauntlet would not work at all. Therefore, they travelled to an earlier point in their Universe to collect the stones, not an alternate one."
It's an earlier point in time, but those timelines played out completely differently than what happened in the MCU after the point of divergence.