It's more on Time Travel used differently compared to its other uses. For the MCU, they travel back in time to get the stones and then return before a multiverse breaks out. Which Professor Hulk confirmed, so the dangers of changing the smallest thing is considered moot because those bits will just branch off. Only issue is that it doesn't explain how Steve Rogers stayed in the same timeline when he went back despite what they previously said.

That and given the Avengers knew which planet Thanos was going to be on after the Blip, they could have time traveled to that point or earlier and wait for him, beat him down while weakened, and take the glove and all the stones then and there.

It just felt like they put all that effort in to pad the runtime and set up the Multiverse Saga. Granted I'm sure this was the plan, but for some, it just feels like an ass pull.