A massive component I see to rest vs. work is flexible scheduling, not just vacation time. You don't need as much time off if you are working at a pace where you are comfortable and not overly stressed. I'm not sure it applies to startup founders who lack the security of a stable job or demand delivery for immediate market presence, but for people with more wiggle room working "slower" and smarter is very rewarding, and in my experience yields higher quality results due to a more ample time to digest ideas.

It also can carry a perhaps heftier social stigma than extensive vacationing if viewed in the wrong light, because of the potential for abuse. If I watch a movie in the middle of the day between working, how is that viewed? Is it different than if I were to take a mid-afternoon bike ride on a Tuesday for a couple of hours? They are both ways that I can decompress and allow me to come back to ideas later with a fresh perspective, and that's sometimes the most valuable thing to me when I'm working.

I would take flexible scheduling over excessive vacation time any day of the week, and I'm fortunate that the software engineering field is one where working from anywhere at any time is extremely easy.