Just pust a few chargers that each charge two cars and reserve the the spots for electrical cars. When electrical cars get numerous add an hourly fee to motivate owners to move their cars when full charged.
This is how it looks at my place in Copenhagen: two charging stations each serving two cars.
https://www.mapillary.com/app/?lat=55.70679767500985&lng=12....
But I also think charging at petrol stations make sense. When considering buying an electric car, at least if the family only have one car, it is a big issue if it can be used on long trips, even if you only do them a few times a year.
And if you are driving to Italy doing 90+ miles/h on the German highways then you will need to charge you vehicle several times. And you will not have time to get off the highway every time. But a 20 minute toilet and coffee break is acceptable.