I have thought similar, that the electric costs will increase for everyone as road taxes, rates, etc. They could do that by simply charging more during off hours, when people are charging. But there is little doubt, everyone would pay more for electric somehow.
Are we forgetting about solar? With the rapid growth of solar adoption, especially with the new Tesla solar shingles and new panels + battery pack, homes are getting off the grid at a rapid pace. Along with small and large businesses, GM announced they should take all their plants off the grid in a few years globally with sun and wind.
Power companies charge based on when the peak load is, and the top-off charging most EVs will do at night, won't get close to the high demand from homes and businesses during the day running air conditioning. And just like with the oil companies, if they get greedy and try to jack up prices, that will just push more toward adding solar + battery pack to their homes and get off the grid.
What this means is electric costs should go down, with lower demand from homes in general and large business users. Even power companies are investing in solar farms. And with homeowners with solar and an EV, the car can get most if not all of it's daily charging from the sun(two car garage with solar can offer up to 50 miles of range).
Whether it's a road tax, fuel tax or toll road(tax), those dollars go to maintain the roadways. So if EVs are not using fuel and not playing a fuel tax, they just pay a higher road tax, but that's based on the propulsion of the vehicle, not in general for everyone. This is happening now.
But what I do see happening as more get off the grid, those left without access to solar will begin to pay more to support the old system of generating electricity.