Those other countries that have it better than we do have healthcare systems either run directly by their governments, or tightly regulated by it in a way that effectively means that the government decides how things are run.
Those other countries also have problems and people with money still go elsewhere when they need help. Rationing exists. Long lines exist. Denials exist. Shortages of doctors exist. etc.
The problem is that the conversation only focuses on the good parts of those systems and ignores the issues.
You can't have a real conversation and claim "have it better" when that may be true in parts but not in whole.
I don't claim the US system is better... or the best. But claiming that government ran or government overregulation leads to better is a lie. The VA is proof of that. the lies around the unACA is proof of that. The ever increasing prices and decreasing results due to government influence is proof of that.
Destroying what we have with something like the ACA isn't proof that government ran will be better... it's simply proof that people are willing to destroy what was working and claim that the destroyers will do a better job if only they have more money and more power.
That's like CA solving homelessness. "more money, more power and we'll solve homelessness" and there's never been more homelessness or less affordability in CA.
