The last mile infrastructure isn't maintenance free and doesn't last forever, so it has to be paid for somehow be it taxes or commercially. Users (in the above situation) paying an ISP are essentially agreeing to a "maintenance contract".
That's why I said "lease to ISP for a fee", the ISP will of course forward that cost to an user, perhaps under extra fees no extra taxes needed, and people who actually use it will pay for it.
BTW: this is how it was with DSL. Title II has this provision, and telco companies were required to lease their lines to ISPs at a "reasonable fee" which was up to FCC to decide (this was so they wouldn't charge ridiculous prices to kill their competitors).
When Title II was reinstated, Wheeler actually excluded this provision, that's why nothing changed in terms of monopoly.
