> In my experience "free" healthcare stops being a thing once you get above certain income level as the service provided by the public healthcare facilities is subpar (waiting lists huge, best specialists often work at private clinics, etc.) so you end up going private but you still end up paying a huge chunk of your income in tax.

My impression is that this varies a lot by country. For example that might be true in Australia and Canada, but not France or Germany. There are many different ways to implement universal healthcare.