[randomdata]

> whether the founders in their 50s had spent their 20s-40s continually trying to start companies.

Apart from some differences in legal paperwork, starting a company and seeking employment are the exact same thing. An employee needs everything else that makes a business: Sales, marketing, capital, viable product, customers, etc. So, unless you think it is the legal paperwork that falters those who are younger, almost assuredly they did. Just like most everyone else.

Lack of capital is what kills most businesses. Statistically, 50-somethings have the greatest access to free capital. Any younger and you're still working on acquiring it. Any older and you have to focus what you have towards supporting retirement. That may explain it more than anything.