I'm curious if this is a calculated move by startups to preserve equity and get some people going crazy pushing your product forward rapidly.

This sounds like the new generation's equivalent of 1980s bosses exhorting people to "give 110%"

plus the nature of a founder's day to day work is very different. 12 hours a day of management, pitches, meetings, and snap decisions is doable for a long time if you can endure the pain.

12 hours a day of complex technical work under sleep deprivation is just not possible, after a few weeks of this your cognitive function will decline to the point you can't do the job right.

Though poor management is pervasive, there are small pockets of sanity out there, in my experience.