Of course it will be paid by people who work. That's how taxes work. Sure there will be people who don't contribute to society who will freeload, but that happens with all taxpayer funded things. Just because there are some people who freeloaders doesn't mean everyone should be stuck having to pay for outrageously expensive healthcare. You think there aren't freeloaders who use roads or lazy students who slack off in public schools. But that doesn't mean we get rid of roads or public schools, just because there's a minority of lazy people. Also what you don't understand, is that not everyone who doesn't contribute to society is just a lazy freeloader who wants to live off others. For multiple reasons people are unable to work. You can't group every person who doesn't contribute to society as a lazy freeloader.
And obviously free healthcare is only going to pay for essential healthcare. Free healthcare isn't going to be used to pay for botox, plastic surgery, gender reassignment, etc. Those will be private out of pocket costs