So...the analogy to healthcare in the US isn't too far off. If you have money and/or a good job you can get healthcare in the US and water in India (healthcare too).
Anyone not earning an income in the US gets 'free' healthcare and has for decades. It's anything but free, it's very expensive.
Just ask any developed nation with socialized healthcare just how free healthcare is, as they all universally struggle to afford it (which is why Canada's wait times are so atrocious despite being held up as a good system).
One can make a great argument for socialized healthcare without pretending it's free. Claiming it's free is just an absurdity, as it's extremely expensive.
My impression was that the only way it's "free" is if you walk into an emergency room with no money. And the fact that uninsured people can only go to emergency rooms (routine issues fester and become serious) is in part what drives up the cost.
In places like Canada the wait times are atrocious due to triaging. If your problem is serious you will get looked at immediately. If it's not, you have to wait. And if you can afford it, you're still free to go to a private clinic. But it does seem like overall health outcomes and costs are better than the US.
So...yeah it's true calling it "free" healthcare is a bit of a misnomer but no one actually thinks it costs $0 to provide. Think of free healthcare like freeways: paid for by tax money for the public good, and occasionally you'll have to pay a nominal toll (co-pay or whatever).
I think people use the term "free" in the same way that the term "free" tricks people into spending more than they would have otherwise. Calling it "free" let's you mentally sidestep the details.
The European Bloc has benefitted from defense/security being bolstered by US equipment/investment since the Marshall Plan. I believe this is what the other poster was referencing.