Not to be flippant, but this potentially has not happened because Tesla has demonstrated it's an unnecessary burden to building a reliable charging network. If you build a charging network intelligently (for example, by putting the user interface in the car, not the stalls) and are motivated to keep it functioning, there's no need for a regulatory agency.
Customers should be selecting vehicles that don't have to deal with the deliberate incompetence of Electrify America.
I've said this as well. It is exactly what's needed. Local Weights and Measures inspectors should be going to EV stations and giving out fines for stations that are misbehaving.
"Gas pumps get periodic state issued inspections. Why not EV chargers?"
From an infrastructure standpoint a gas pump (and related tubing, tanks, filters, nozzles, etc.) is quite a bit more complicated and fragile than a charging receptacle.
A charging station really shouldn't be much more complicated than a streetlight, minus the UI and billing components.
All of this to say:
I don't know how often electric charge stations should be inspected but I hope it would be quite a bit less often than a gas pumping station ...
You might be thinking of a level 2 AC charger which is really just an intelligent relay, but a DC fast charger is a completely different animal. It has to take 400-600VAC and convert it to variable voltage, variable amperage DC and serve it to a very temperamental load. The cables themselves are liquid cooled. Much more complicated than pumping a metered liquid.
Anything that involves dangerously high amounts of electricity and an interface with the general public should have a regular inspection interval. You will end up with dead end users if you do not.
Ensuring that the gas pump actually pumps out the amount of gas the customer is being charged for is something that shouldn't apply to EV chargers since the vehicle itself can monitor the amount of electricity it receives but there are safety issues that certainly need to be tested for and if government subsidies are being received, SLAs that should be enforced with verification.
Probably part of it is that gas stations must store gas in underground tanks, which can pose an environmental hazard. Topside leaks from faulty valves, hoses, nozzles, and human error can also cause an environmental hazards.
There's also a matter of accuracy in how much fuel you receive and how much you pay for. I'm assuming it's much easier for an elective vehicle to independently verify how much of a charge they received compared to a gas car.