The movie is listed at 152 minutes, so if you stepped out at 2 1/2 hours, all you missed was the credits.
I think the last 3-hour-plus movie that i saw was Return of the King. I’m not saying that none have been made since then, but they are far from the norm.
Well, it felt a lot longer. Anyway, I usually try to find a seat before the house lights go down. Round these parts, if a movie is scheduled to “start” at a given time, that’s just when the ‘Coming Attractions’ previews start playing, so that adds on several minutes at least. If I were to wait until the movie itself starts, I might not be able to find a seat. Plus, it’s dark in there.