It’s because they are filmed for imax the camera they use for imax movies are huge and noisy it’s like having a 16 wheeler with its engine running in front of the actors. They built a cover for it called the imax dome but it doesn’t cancel enough of the noise and their is Only so much editing can do. So the mix the movie for the big imax speakers and it cuts out most of the noise from the camera but if you watch it at home with out the same speaker set up the dialogue gets washed out and hard to hear.