Minecraft UHC (ultra hardcore) competitions are one example of longform youtube series. Each episode is 20 to 30 minutes; you'd probably watch a couple of different people.
I assume bigger channels make money from doing it.
I'm currently watching LapisDemon (associated with the now broken ZipKrowd server) and Xisuma (Hermitcraft) playing as a team and I dip in and out of other viewpoints.
This definitely reduces the amount of telly I watch.