If I fall into a volcano, I'd like to know how much time I would have to call for help.

For Science!

Or perhaps they're just trying to show off. They got money to burn (pun intended) and they want to entertain with it. The usual motive is YouTube subscriptions, because the attention feels good. The internet makes it easy, but everyone understands they have to work for it. It used to be that only people who could distribute videos in a mainstream channel like television or radio could afford this attention, but now we have countless millions of users, all in a bid to shout, "Look at me!" as loud as possible, in a competition for attention and "lolol 5 stars" comments. Unfortunately, there's no standard as to how to get it, so people will make outrageous videos like this just to stand out. As the saying goes, if you got it, flaunt it.