"Greed is good. We should all be as self-interested as possible."
"Okay, I greedily want Single Payer Healthcare. I selfishly want Public Housing."
"... "
Society doesn't exist without society. Healthcare, education, housing, and many more goods and services are the basic things that a society needs to function. It's the same with drinking water, food, sanitation, waste management, and in modern society, roads, telecommunications, ports, shipping lanes, outdoor spaces, recreation facilities. I won't go on because it's a bloody long list.
Without these things there is no society, no public, no individual. It is an aberration that any of these things are treated as private goods and services to be bought and sold at all. They should all be public, cared for collectively, and free-at-the-point-of-use. That's not lazy. It's just an acknowledgment of what human survival involves. And humans are entitled to all this because if they don't get it they fucking die. Healthcare, education, and housing are just the start. Societies that don't provide the essentials and a little bit more cannot survive. Ask the Tsar or FDR what happens when enough people can't access the basics.
Ask any society that tried to concentrate labour without water treatment. What's that, they died off soon after because the people needed to do the work died of dyssentry and there were no engineers to build sewers, no doctors and nurses to heal the sick, and the grave digger died of pneumonia in the night because they'd been evicted in -40°?
There's an argument, and we're in the right place for it, for the common ownership of all the means of production. Anything else is unsustainable. It doesn't even need a moral argument that denying healthcare, education, and housing is cruel af. It is but it's beside the point. In private hands, as a matter of logic, these goods and services will undoubtedly fail as they have always failed.
Additionally, we are now at a stage of history where almost all production is socialised. As we saw through the pandemic, if someone doesn't do their little bit in the logistics chain, the chain breaks and the goods don't arrive. Private ownership creates unnecessary risks in these chains. And the thing with risks is that they materialise, given enough time.
Putting all this power into collective hands is a longer term goal. Putting the absolute essentials, such as housing, healthcare, and education, into public hands is how to ensure that we survive the middle term to make it to the long term where we can achieve our other goals. As it makes little sense for the public to charge itself (although believe be, the libs will find a way if anyone can), this means making these provisions free for users.
Ask your interlocutor of they want a doctor when they're sick, a plumber to install their sink and toilet, an architect to design their house, a new Tesla, a serviceable road between home and work, a movie to watch on a Friday night, a truck to be driven to their supermarket with boxes of cereal and frozen meals, etc, etc, etc, etc, etc basically anything considered necessary for them to survive. Ask them if they want employees to concentrate on the job rather than trying to wait tables and carry a tray of food with a gangrenous leg, or trying to enter data while worrying about the eviction notice that came in.
Ask them if they want the valedictorian with the brain power to invent a technology that makes flight transport carbon neutral (and so sustainable) to give up their dreams because of the cost and instead spend their life putting tickets on cars parked in the wrong bay for too long. It's not my annual holidays to the Bahamas under threat from climate change, bozo, because I can't afford them anyway.
We need all those people: to receive an appropriate education; to have somewhere to sleep, wash, and unwind so they can rest to be able to do their job without having a breakdown; to have access to a doctor to manage their disease do they don't give it to your kids at school; etc; etc; etc.