What really bothers me about the plot is that the whole movie takes place five years after the events in Infinity War. And, although there is time travel, the events are not undone.
When I watched Infinity War, I was pretty sure that they would come up with some idea in Endgame to undo the snapping and the disappearance of half the living beings in the world. I mean, if the population of the universe is divided by half, there would be tremendous consequences. They should have traveled back in time to avoid that happening at all.
But Endgame not only did not do that, it fast forwarded this five years in the future. People are back after five years, but then, there has been five years! The consequences are huge, and they did not even begin to addresss them.
If half the population suddenly disappears, there will be chaos in cities, bankrupt businesses, abandoned places, vacant properties, broken families. The world would be a bizarrely different place.
If, five years later, all these people reappear, that is chaos again. Five years later, the world would have accommodated with half the population. Bring all these people again and there will be chaos again: shortage of food and supplies, not enough goods and services for everybody, not enough room for everyone. Not every family would have left a spare room waiting for the missing ones. No supermarket would wait for half its customers to suddenly reappear.
I mean, the events in Infinity War triggered consequences to the whole mankind, and which were aggravated (and not mitigated) in Endgame.
How are they going to deal with it and keep it realistic? Now every new movie will take place after the events in Endgame, I suppose. Is the world depicted in these movies be the same as if such traumatic events never happened?
The next movie is Spider-Man. Peter Parker will be back at school. Have his friends grown up? Are they graduated? Or are they all in the same class, as if five years have not passed for half of them? Is there enough space for him in the class or in the school? Are his relatives older? Some of them may have died during this period? Are they going to think of every detail in day-to-day life that necessarily change during this 5-year gap in which half the population was missing? And are they going to do it in every movie in the MCU from now on?
Of course not. The consequences are too many, and cannot be addressed. Instead of creating events that affect the MCU characters only, they created some that profoundly change the world. And they cannot keep track of such huge changes, which will make the MCU less logically plausible from now on. There will not be a logical continuity to these events.