I prefer to watch films that are good to great, no matter the time as long as the artists know how to use the time well and make the work worth to watch. There is fantastic works that span the whole spectrum, from short films to lenghy films, and there is trash all the way too (Some director compared it to paintings, that range from tiny papers to whole walls). If we really think about it, any anthology series like Black Mirror and The Twilight Zone 1959 are just a collection of short films that share a theme, some recurring stage crew, and etc. If i am short on literal time, i have no problem stopping and taking multiple sections to watch a film (purists have some point that it loses a little of the impact some times, but most of the time it really does not).

I think it is 2 reasons for the trend:

• Cinema-at-home technologies just keeps getting so much better all the time, and it is already pretty great. Streaming and 80 inch 4K OLED TVs are just the latest iteration of a process started in the 1950s with tube TVs, and if VR-AR glasses popularize they will be the next. Cinema Studios and Cinema-at-theater companies had to invent new immersive technologies and art forms to stay competitive, from the rectangle screen form (16:9) until IMAX 4-D etc. They also artificially benefited the cinema-at-theater by having the release window schedule (3 months in theaters, another 6 months to dvd, 1-2 years to tv, etc), that has been diminushed but it still exists (6 weeks to 2 months in theaters i think), and in our FOMO infested culture this might make theaters stay in the long run in some form or another. But overall, home has never been such a sweet place to watch cinema.
• The endless rat-race to keep cinema-at-theater competitive with cinema-at-home has eventually made that only Blockbusters in high tecnology cinemas are attractive enough to most people, and to pay for all this sensorial spectacle that ranges from the theaters to the films themselves, the scale of capital costs in the whole industry has just risen to the roof, and now the tickets are usually very expensive (and foods drinks etc). The average consumer in turn, feels that going to a film in a theater has to be WORTH it, has to be better than home and has to compensate for the high ticket (and foods etc) price. This means that films have to be a Spectacle that is highly sensorial and lasts a lot of time to become a memorable Event in the persons day, week or month. So, longer run times.

There is a cinema industry that is already more advanced in these characteristics: it's Bollywood, with the Masala genre (i.e. a spectacle that has to please the whole family, and they include at least some romance action drama dance music in every film) and many hours of lengh (4hr is not unusual). Because the average indian is poor, and they go to the cinema rarely, so the indian studios have to make it worth it, an Event for the whole family, like Hollywood has to now. There is also something of a Music Show vibe, where the audience cheers and claps when the stars appears on screen, and actively engages with the film throughout (booing a vilain , lamenting a death scene, etc), it reminds me of the marvel spider man 3, but times 10 and all the time, it's a cinema-at-theater experience also unmatched by home, because of the collective element. Maybe Bollywood is the mirror that Hollywood has to emulate now, instead of the other way.