Look at Avatar (2009) vs the sequel. The original was ~3 hours long, and a pretty ok movie. Kept the attention of everyone in my family from beginning to end. The sequel was 15 minutes longer, but we gave up before the end of the first hour because it was atrocious, particularly the paper-thin "dude, bro" writing.

Avatar 2009 had cutting-edge visuals, but by the 1.5hr mark I was bored. I don't remember the ending, might've walked out.

The look of thee original Avatar was something you had never seen before but the story was essentially a reworked version of the overrated Dances with Wolves. The latest Avatar is basically a remake in an aquatic setting and it has none of the visual freshness that the original had. I dutifully watched it when it hit whatever streaming service but it was sort of a waste of time.