Those countries are smaller and most likely have more functional governments than the United States. Having a dysfunctional government is a feature, not a bug, but it does mean that the national government would do a bad job running the health care system.
Germany's nearly 90 million people. What about a 90 million person health system can't be done with 300 million? At what point does this magical impossibility kick in?
Having just visited the EU I can tell you the working folks in those socialist countries are pissed they have to support immigrants who arent contributing.