I know you're referring to the tendency of many Youtubers to not shut up, but every streamer I've seen has invariably had as part of their setup the "massive drink" in large part because incessant talking requires heavy liquid consumption. So I actually imagine most YouTubers are actually aware that talking is not the wisest idea in a dehydration scenario...

It's not exactly uncommon for someone lost to record themselves. If he died, the recording could give family and friends closure.

I'm sure his family would appreciate his grunting, groaning and profanities.