Collecting and accounting for payment is overhead. If something is "free", then that overhead can be reduced or eliminated. On the other hand the basic purpose of charging for anything is to allocate limited resources, so the task is how to match supply and demand.

But saying it is "grossly inefficient" not to charge for something makes no sense to me. That's not the issue at all.

The thing that is grossly inefficient is the manner in which services are paid for when it involves doing it indirectly via tax authorities. The overhead can't be eliminated when it is done that way - it requires a contingent of administrators and petty bureaucrats.

The obvious problem with providing stuff at no charge is that it will cost too much to supply it, and people will waste it, but that isn't what I would call overhead, and I don't think you are talking about that.

Presumably you support per-mile metering on public roads then?