That would be a fair point if we were talking about like, small businesses in markets that are well-suited to competition, but that is not mpdern ISPs.

Iirc, much of the backbone of the US's fiber optic cable network is publicly owned anyway, it's just the "last mile" that's privately owned, which is the local lengths of fiber that run through neighborhoods to individual residences. But most of this infrastructure was also heavily subsidized by the state, so the way I see it, ISPs are essentially leaches that extract rent from a system paid for by the people and (directly or indirectly) built by the state. Why should we let them collect profit from a network they didn't build when we could own the entire network publicly and set monthly rates to break even, rather than generate a profit (which would keep prices very low, as seen in Every Other Country with mainly state/municipally owned ISPs).