If you only work a minimum number of hours within your field, you are unlikely to emerge as one of the peak achievers or thought leaders in your field. That's just because you learn more from experience, and working more hours gives you more experience.
You can extrapolate from there what this means for companies and individuals.
I am not at all saying that companies should ask people to work long hours. (I run a software company, and we are super-lax about hours, people showing up at the office, etc). But I am saying that if an individual wants to be an expert in a particular field, that person should probably work a lot (and probably wants to work a lot anyway, due to interest in the subject). This doesn't necessarily have to be at the company; it could be at home, on personal projects, whatever. But the deeper and more challenging the project is, the better you learn, and it's easier to have one project that is deep and challenging than somehow to have two in parallel. And if only one is deep and challenging, then you are sort of idling with half your time. So there are basically two paths to this kind of deep work: work for a company, make sure you get a project that's really good, and then work hard on it; or go do your own thing, make sure you have enough money somehow, and work hard on what interests you.
This also means that "work-life balance" is not a thing for experts the way it is for normal people. But that's fine, because for these kinds of experts their work is a serious part of their life and the two things are inseparable.
Of course if you don't feel this way about what you're working on, that it is a serious part of your life, then this strategy doesn't make sense; and I would not encourage people who don't feel this way (who are the majority of the population) to work that hard. I am just pointing out that there are some of us for whom a different life strategy is best.