Do you watch TV? Then you still watch videos that are 30 mins or longer. The difference is the format and quality of those videos are better at capturing your attention, that's all. An hour long YouTube video that ISN'T structured like a TV show of some sort (like sketch comedy, news show, or a documentary) is just going to be a boring, terrible product.
I think there's a temptation to think of "YouTube videos" as being that most common 2 to 10-minute talking head format. But you can't just expand that format out to an hour and have it continue to be as engaging. It needs to morph into a different kind of production.
Here's one of my favorite hour long YouTube videos from a great teacher named Nick Zentner: