> If the trades aren’t happening, the necessary mutual benefit is not present.

Then why does the US governement fund roads? Because there's a collective bargaining / coordination problem. It benefits us overall if we have them, but that doesn't mean that a profit could be usefully generated from maintaining them, or that this is the best way of running the system (we want to maximise use of the infrastructure, not discourage use with high usage tariffs).

The is fundamentally an economic argument, albeit one that recognises value beyond monetary value.