I generally believe most movies should be shorter and that there’s a lot of room for addition by subtraction. That said, if a movie earns its runtime then I don’t think there’s an upper limit to how long it can be. Lawrence of Arabia is 3 hours and 45 minutes and it’s incredible, I don’t think I’d cut anything in it besides the long black intro screen which is a relic of its time. I would say justifying that run time gets exponentially harder past a certain point.

With Way of Water sitting at 3 hours and 12 minutes I do think Avatar 3 needs an intermission if it’s going to be longer. Asking people to sit and be fully engaged for 3 and a half hours is a big ask and having a chance to go to the bathroom, get snacks, stretch your legs, etc is needed for something that massive