I think the parent is asking/claiming that public options are almost universally less desirable than the product of self-interest in the presence of competition, so their main effect is just to ensure that the private would-be monopolies need to actually provide a good service.

In domains like Internet infrastructure and health insurance which are empirically pretty terrible when there's no public option, I think there's a lot to be said for that argument.

Is it "fair" for a monopoly to have to compete against an organization that has nearly infinite resources but terribly inefficient operating ability? I don't know. Maybe yes, maybe no. Is it fair to huge ISPs to impose net neutrality on them? Maybe yes, maybe no. But it's no less fair for them than not having net neutrality would be for companies who want to use that infrastructure. It's certainly no less fair than life would be for a child who can't afford access to health care in a black market-like total laissez-faire economic system. I'd prefer to live in an imperfect implementation of capitalism that tries to regulate out negative externalities when possible (despite often failing) and provide as much fairness for as many people as possible, to one that provides so much "fairness" to certain corporations that they can make the game unfair for everyone else, people and companies alike.