When used in a social context, "free" has a different meaning than in many other contexts. It does not mean, for example, "there is no cost for this thing". Rather, it means "the person receiving this thing is not responsible for paying the costs associated with it (at least not at the time)".

Free health care doesn't mean "nobody gets paid to provide health care", it means "patients do not pay for health at the point of service".

If you'd prefer that we use some other term to describe this, please suggest it. I do find it interesting that the Scottish NHS uses "No fees at point of service" as part of their branding (or did, back in 2019).