Lack of single payer healthcare also keeps tons of people from starting a business for themself. By the time someone has built up enough experience to have a good chance of making it on their own, they'll have a family depending on them so they can't take the big risk of leaving a steady job.
The spouse/kids have a medical issue that isn't a huge deal in any other civilized country, but you're now dependent on healthcare subsidized by your employer for them to get treatment without bankrupting the family. Most people simply can't afford to give that up.
Also housing. Most people can't afford to risk lean months while starting a business because housing and other necessities are taking such a huge chunk of everyone's paychecks now.
Things are this way by design.