The key to personal fulfillment is not work/life balance. Work/life balance implies that work and life are two separate things, which is incorrect. When you go to a job for eight hours a day, your work is a huge part of your life.
Distinguishing the two leads to escapism. Living for the weekend is undervaluing your very existence.
We should instead strive for alignment between work and life. Life inspires work and work sustains life.
I believe the happiest people formulated their own meaning. A vision allowing them to navigate through life. Reaching a vision implies work, a life's work.
Is it healthy to dedicate your life to your work? A workaholic has no sense of personal hygiene. A smart worker understands doing your best implies eliminating busyness and taking care of your health while benefiting others, which often results in working less.
If you want to work 14 hours a day, go for it. You won't sustain it for long, but at least you will experiment the impact for yourself and thus make some progress toward what matters most.
Similarly, try working two hours a day. You wish you could do more for others, or at least for yourself.
A pro shows up to work not because he/she has to, but because not showing up would result in madness.
Can we live in a world where no one has to work for the sole purpose of paying the bills? That's a better question.