Sub-par care is excellent when the current reality is that most people don't get access to any care at all.
You must understand that the vast, vast majority of people don't go to doctors. They don't have dentists. When a poor person is in pain they will continue to be in pain until the pain goes away or they die.
When given that versus a shitty but free healthcare system, who wouldn't want to see a doctor? To get $5 prescriptions to medicine that can help them?
And remember, this is assuming the healthcare system will be shitty - universal healthcare has never been repealed in a country that has implemented it. Don't you think if the citizens of these countries were so fed up with free care, they would be protesting and electing candidates that promise to dismantle it? Even Boris Johnson has to tiptoe around privatizing the NHS because he knows how wildly unpopular that would be, even among his conservative constituents.