I agree with you on this, it's seem that if a sci-fi movie isn't a 2 hour action packed bonanza people can't keep their focus. The movie had incredible cinematography and the atmosphere you got was spot on
Watched Dat Boot 1984 a few days ago. An old movie but absolutely phenomenal. It shows what life was like inside a claustrophobic german u-boat during WW2
https://www.imdb.com/title/tt0082096/