I think it's a fair premise that the majority will never / can never enjoy working 70 hours per week. It's essentially impossible to match so many people ideally up to financially rewarding tasks they'd enjoy doing for that amount of time each week on a persistent basis. I'm skeptical there is much of anything people enjoy doing 70 hours per week; I've only known a few people that even liked to get that much sleep. In the past I've known a few gaming addicts that played ten hours per day, but, that's an addict, they have a serious problem.

If you have a family, 70 hours per week becomes threatening to the well-being of that family unit. Are there exceptions? I'm sure. That's all they are though, rare exceptions. A bunch of that time should rationally be spent exploring life with the kids and spouse, partaking in new shared experiences together, which is what bonds people together for the long-term.

I don't mind working eight hours per day, seven days per week. Up to ten hours if I really need to get something done. I won't do that for anybody else other than myself though, for my own projects/businesses; I won't do it under any circumstances for some middle management moron clown boss or company I don't own. My bills are around a thousand dollars per month right now, I can meet that working part-time for $15 / hr at a convenience store if I feel like it, or doing low volume contract tech work on the side. I've been working six or seven days per week for 20+ years straight at this point and I have rarely suffered burnout, because I've spent that time working on what I wanted to, doing what I wanted to, when I wanted to, with no boss. If I want to sleep all day, I sleep all day; if I want to work all day, I work all day; if I want to sleep during the day and work all night, I do that. That's not normal, and it can't be replicated by the majority of people. I also don't have a family; if I did, I'd have a different schedule because my priorities would be different, working 7*10 would be a serious disservice to that family, it would be unfair.