If we're talking about universal coverage in other countries and the potential for crippling healthcare debt in the US, then pointing to the ACA really doesn't help your argument here.

First: 400% of the poverty line is not very high, so premiums for people just over that line can still be very unaffordable.

Second and more importantly, ACA coverage is generally not very good, especially at the low silver tier covered in that %10 income cap. Pointing at the ACA ignores the fact than plenty of people with coverage still are faced with insurmountable debt, sometimes loss of home, and often bankruptcy. As long as hundreds of thousands of people each year have bankruptcies tied to medical issues, there's nothing about the US system you can point to, be it Medicaid, Medicare, ACA subsidies or anything else, that can surmount the argument that the US system fails people in this respect when compared to other countries with universal coverage.

I'm not saying those countries are always better in every respect, but one thing they have is that they don't cause their citizens to lose their entire way of life, their home, and ability to live above poverty levels when faced with treatable medical issues.

Actually 7% in France, basing it off budget for 2017.

The tax burden is higher because education, public transport, agriculture and social (mostly retirement) are paid in tax rather than mostly privately.

US has the private system for retirement plans and it sometimes fails utterly. The nationalized one does not, though it may not be as big of a payout. And education saddles people with debt, as well as causes cost (admin) inflation.