One tiny little example has been in operation for decades in the unincorporated areas of Yuma, Ariz. If you want fire service, you subscribe. Or, you carry a high limit credit card at all times.
That is for fire service only. Roads and police and military and other federal protections still apply
I think it happened in Tenn, as well. And the guy who didn’t pay his bill, watched his house go up in flames.