If freedom of association is incompatible with socialism, then I wouldn't consider myself a socialist. Labor unions owned by the state are almost completely useless, as we see in Egypt, Nazi Germany, the PRC, and so many others.

That being said, the United State's higher rates of privatization are associated with a lot of negative outcomes. Our healthcare system is a lot more expensive with worse outcomes than other countries, our legal system is extremely hostile to the poor and lenient on the rich, massive amounts of money are sunk into the military, our infrastructure is breaking down, homelessness is rampant and getting worse, and so on.