If that thing throws a fit and youtube demonetizes the channel and/or pisses off the advertisers such that they don't advertise on his channel, Linus is done. And I suspect everyone involved knows this.

You could argue that he doesn't need the money or the hassle or anything, and in a sense you're right. But I'd guess he also wants to do right by his employees who would be out a job if that happened. Maybe he could sell the business, but he's also the very public face of the business; and what would it be worth if he no longer was?

All assuming he's not enthusiastically supporting all this, which I'm not sure is a reasonable assumption to make given the last 3 years.