If you talk to people who immigrate to US from those countries with national health insurance, you’ll find that what you claim above is by no means a consensus.

For example, I immigrated to US from Poland, and in my opinion, US healthcare is much superior to Polish socialized healthcare, in terms of quality and availability. Cost wise, it’s more expensive, but my out of pocket costs are too small for me to care about: my employer pays for health insurance, which is a benefit on top of my wages, instead of being subtracted from my wages like in Poland. My deductible is low, and so are my copays and out of pocket maximums. This is opinion shared by most of my Polish friends in US.

Back in Poland, socialized healthcare is held in low regard, lines are long, quality is low, and a lot of people, especially in cities, pay for healthcare from private providers anyway.