10 Movies That Made Things Complicated To Hide Their Flaws
8. Avengers: Endgame
We could all sit around for days debating the intricacies of the plot of Avengers: Endgame or whether you can just accept the writers' version of the rules of time travel as appropriate to the universe they created and move on with your life, but there's no getting around the fact that the "new" rules covered a multitude of sins.
The scene in which the Avengers explain how conventional thinking about time travel - and pretty much every single time travel movie you care to mention - is wrong is the insistent attempt to explain away the plot-holes created by how the story unfolds. By apparently basing it on sound science (and it's no surprise that they use the film's most scientifically gifted characters to do it) Endgame fundamentally establishes a complex time continuum theory that means they can do anything they like and get away with it.
And then, when even that didn't answer everything, the film-makers enigmatically threw out mentions of alternate dimensions in just vague enough a way that they'd sound mysterious. That any of this worked is the true mark of Endgame's success.