Avatar, Way Of The Water, a 3 hour movie, broke all sorts of sales records (though # of tickets sold data apparently isn't out yet).
Heck Avengers End Game was 3 hours long and it sold 351 million tickets.
I do think you get less of the repeat sales now days vs even in the 90s, just because there are so many more movies coming out, both in Cinema and on streaming platforms, but that doesn't say anything about people's willingness to attend long movies.
