Not snarky but, as opposed to what? No school? An arts degree? Or are you looking for an alternative to an undergrad biz school degree that's more start up focused?
Plenty of school now seem to have entrepreneurial programs. Maybe a undergrad school that has an entrepreneurial emphasis is your best bet?
as opposed to STEM degree
I think it depends on where you want to fit in a start up? For example, if you want to do customer acquisition then marketing (and analytics) which is more biz school than STEM might work. Product dev, same. But if you lean to something more technical then go more STEM-y.
Two ways to make money, financial speculation or selling to other
people. Most prefer the latter -- less of a chance of going broke.
To the extent that any business school (undergrad or later) introduces
you to other people, that helps.