The wires aren't the problem; you've already got a power grid carrying kilovolts along the same streets to power the buildings. The cost is the charging ports. So start with one, reserve the space for EVs and make it expensive.

Then people won't want to use it. Most of the time they'll charge at work or some restaurant that installed a charging port to drive customers to its business. Which is why you only have to start with one -- the first one on the street is just for emergencies. You might have ten EVs in the area and one charging port because at any given time only one person is willing to pay that much to use it. Which also means that it's regularly in use and can recover its costs quickly. But then it's there if you really need it, so more people can feel comfortable buying EVs.

Then once there are more EVs, you can install more charging ports -- they're paying for themselves, after all, as long as you don't install so many they don't stay in use.

Then once you've paid off the capital cost you can lower the price, so more people use them, so you can build even more. When you have 10 charging ports but 9 are already paid off, you only have to charge 10% of the original premium to pay off the 10th. So in the long term you still end up with plenty of charging ports on the street at only a slightly higher price than they are in other places.