I've worked extremely long hours and there's a very big difference to me between working on a saturday on green-field development where what you're doing takes time but isn't particularly full of surprises - and trying to grind out a hard to find bug instead of enjoying the outdoors. I don't hate hunting down bugs myself - but dealing with fatigue from overwork while trying to find a needle in a haystack is much different from being able to cruise through some reqs like a badass using half your brain.

It's quite likely that the billionaires putting in long hours are doing so in tasks that are diverse and decisive enough to not be soul crushing - while outsourcing those soul crushing tasks to their subordinates... in fact if that isn't the case then they're executiving wrong.

Finally, being a found who benefits directly from every penny your company earns differs significantly from working plebs that might just be randomly fired tomorrow and will never see any benefit from the company doing slightly better. The motivation is there for Musk in a way it isn't for those who surround him.