It's basically a tradeoff between wasting your personal life or wasting your professional life. If you get a job that is truly 9-5 (or maybe even a bit less), it leaves a lot of time for forging friendships and relationships and learning hobbies while you're still young, doing sports, seeing the world.
Founders usually feel they're missing out on all or most of these. And some of them probably feel like they don't really have a choice - maybe their specialty/resume is one that's difficult to get hired but skilled enough to make money on their own.
However, plenty of jobs take all your time and still feel meaningless. Many (most? - median personal income in USA is $42,000) don't pay enough for people to really socialize much anyways or do most of the hobbies they might enjoy or travel at all. Generally, having the choice of "HOW should I 'waste' my twenties?" is a fairly privileged one.
Founders usually feel they're missing out on all or most of these. And some of them probably feel like they don't really have a choice - maybe their specialty/resume is one that's difficult to get hired but skilled enough to make money on their own.
However, plenty of jobs take all your time and still feel meaningless. Many (most? - median personal income in USA is $42,000) don't pay enough for people to really socialize much anyways or do most of the hobbies they might enjoy or travel at all. Generally, having the choice of "HOW should I 'waste' my twenties?" is a fairly privileged one.