Yeah, I agree with you actually, more than you realize. I'm writing a novel which uses string theory / ten dimensions of reality to explain different "levels" of time travel. The Avengers used sixth dimensional time travel, constrained to probability, which would create a branch universe. The TVA/Loki could've used the fifth dimension (constrained to timeline), which means Mobius and Loki were always in Pompeii, and always have been. Fourth dimensional time travel (linear time) would be used for prophecies, and everything above sixth goes into fully alternate realities: for example Dark Dimension is a ninth dimension jump (different physics).

But honestly I don't think something like this will wind up in the series. I just like talking about my weird novel lol