I guess to me the crass eyeball-harvesting of MrBeast seems like exploitation of everyone involved with the only meaningfulness involved being profit. But I realize based on stickfigure's response that different people find different things meaningful, fair enough. Which is different than saying "just getting lots of money is meaningful for me" -- that is a different axis than meaning, and I'm unlikely to be swayed otherwise, although some people don't need meaning they just need money. It was hard for to imagine anyone is doing it for anything but the money at MrBeast, but different people are different and some of them are hard for me to imagine, fair!
I read the PDF; profit wasn't on the list of KPIs. In fact there was quite a lot of invective against it; he'll kill expensive projects just because he didn't think the quality was good enough. Of course $$ is related, but the focus really is on the eyeballs.
I worked in porn for a while. I found the work fun and meaningful. Not every mission involves saving the world.
I agree that doing meaningless work is soul crushing even if well-compensated.
It seems like it ought to be possible to do meaningful work without working 80 hour weeks, but maybe not!
And owning your own business isn't necessarily an easy 40 hours a week and don't think about it when you're not working, but sounds like you did have a lighter schedule? Or actually you didn't mention that! If you traded a 70-hour week as a well-compensated employee doing meaningful work for a 70-hour week being your own boss with possibility of making more money doing meaningless work -- yeah, I would make the same choice between those two! But I'd rather not have a 70 hour week, be reasonably compensated, and do meaningful work, if that were an option...