“That is true, but they only carry the electricity very locally. They aren’t carrying it for three million people trying to charge their EV’s. This will overuse the system.”
Nope. Charging current is less than your peak load when everyone comes home and turns every thing on!
Actually peak load is during the day, lots of capacity available for nighttime charging. So much so that you can arrange with your electric provider to use it at discounted rates at late hours; car can be programmed to charge during cheap hours.