Time doesn't scale
But bravery does.
The challenge of work-life balance is a relatively new one, and it is an artifact of a world where you get paid for showing up, paid for hours spent, paid for working.
In that world, it's clearly an advantage to have a team that spends more time than the competition. One way to get ahead as a freelancer or a factory worker of any kind (even a consultant at Deloitte) was simply to put in more hours. After all, that made you more productive, if we define productivity as output per dollar spent.
But people have discovered that after hour 24, there are no more hours left. Suddenly, you can't get ahead by outworking the other guy, because both of you are already working as hard as Newtonian physics will permit.
Just in time, the economy is now rewarding art and innovation and guts. It's rewarding brilliant ideas executed with singular direction by aligned teams on behalf of truly motivated customers. None of which is measured on the clock.
John Cage doesn't work more hours than you. Neither does Carole Greider. Work/life balance is a silly question, just as work/food balance or work/breathing balance is. It's not really up to you after a point. Instead of sneaking around the edges, it might pay to cut your hours in half but take the intellectual risks and do the emotional labor you're capable of.