Today, top-50 movies, on average, are 8 minutes longer than they were in 1980 (110➡️118 min)

I bet a majority of that is credit rolls

To be clear, this does NOT imply that people are just less creative today. Amazing artists & ideas are out there. What it does suggest is that studio tolerance for and audience interest in standalone movies has declined.

Yes it does. If people have a preference for sequels, it's because there might be a vestige of something they liked before instead of whatever woke trash they are trying to shoehorn in.