Hi Sasha. In those countries, insurers are forced to abide by regulations that American insurance companies would never dream of. Dutch insurers are required to offer all primary and long-term care at a fixed price, and they are mandated to operate as non-profits. Over 80% of their healthcare system is publicly financed.

https://www.commonwealthfund.org/international-health-policy-center/countries/netherlands

I suppose you make a good point that it's technically possible for private insurance to exist while still having universal coverage. Perhaps I should say that "for-profit health insurance" is the problem here.