Oh yeah, some of it doesn't make that much sense but part of it is real. If you study your Feynman diagrams, positrons could just be electrons going backwards in time. I think it might make more sense if you watch it a second time.
Avengers Endgame is a little worse, no idea what Ironman had in mind when he said the answer was the EPR paradox. I think even today it still doesn't really have a good answer. And it has nothing to do with time travel, just instantaneous communication.
I still enjoyed them, movies are really fantasy.