@Daojoan I have thought about this several times. I'd say that most movies still follow conventional timelines and stories, because the stories are interesting enough in themselves.
However, over the century of cinemagoing, audiences have become more literate and used to stories, flashbacks etc. It's possible to add more complexity, weave plots so that there's more of a moment to the "surprise". And make repeated viewings more enjoyable as we see more details.
I bet that half the movies in the top 20 (other than blockbusters) would have been unwatchable in previous decades because audiences hadn't grown up with that grammar of movies. At the same time, many of the classics we still revere now are because they subverted the expectations of the time.
I'd love to know some examples of current movies that you think are overly complicated or incoherent. Oppenheimer is an obvious target, but for me it took me inside his thought process as he recalled his life, jumping back and forth between events.
Agree with Lost, although I understand that the writers got a bit stuck early on after the "mystery of the week" format got tired and they promised something that they couldn't actually deliver.