I was raised on essentially this. My (Russian) family and I all (when possible) take ~1 hour nap around afternoon and sleep (all incredibly lightly) for ~3-5 hours at night. If I do not take this nap I feels very tired for the ~2.5 hour window ~5-7 hours after I wake from my ~3-5 hour sleep, and the following night I will require 7-10 hours of "sleep" to feel "fully rested". During these 8-10 hours I will not sleep soundly and spend ~1-3 hours of that time lying in bed unable to sleep but fully weary and exhausted.
Personally I prefer this polyphasic sleep, because I have more functionally active waking hours and I experience very vivid and memorable dreams which, though rarely "pleasant," are always incredibly moving and feel critically important to me
I do not know if this is universal or if it is genetically unique to my lineage, as again, I've noticed many in my family are the same way as me in this regard. I assume others must then be this way as well, though they may not have been raised thinking this behavior is normal or desirable.
The issue comes with scheduling, and this is not always possible. Luckily most of my family is well-off enough to demand whatever they so wish in their vocation. I think most startup founders might be this way also.