But I don't know! I truly wonder how many businesses have been run into the ground because of a kamikaze attitude to working hours. But I also wonder how many businesses missed gigantic opportunities while the founders were off doing unimportant things like putting their kids to bed. Neither are measurable, as far as I can see.

If anyone has any stats on this, any at all, consider me recommended!

Stats don't even matter, because at that level of financial independence, it's a personal choice whether you spend time with your family or pursue another business opportunity.

There's always a limit on how much time you can spend per day, and this limit is far below the time you are awake. Push it too far, and you do not only lose your working power, but also your motivation and your inspiration.

I agree entrepreneurs can get burnt out, but at that point it's become a "job" and is probably time to move on.

there are limits to stress your body can sustain, and your mind can be totally disconnected with it, pushing and pushing.

The assumption is not only incorrect, but I believe it is exactly reverse: Losing passing is one of the consequences of a burn-out. It is not a cause, but instead one of the (most visible) symptoms.

If your only business advantage over your competitors is a willingness to sacrifice your life for money, then you'd better either be okay with doing so indefinitely or be making enough money you can call it quits before you're too old to maintain that pace.

For founders, and really anyone heavily invested in early stage startups or companies looking for a lot of growth, responsibilities are 24/7 and the line between work and life get blurry, and it's a lot more difficult to make sure the balance is there, but also a lot more important.