This could break down a number of ways. I'm not entirely sure about the financials behind these chargers but there's a bunch of companies that operate them, and they charge to use them. I'm assuming the private businesses where they are installed are paid either a portion of the profits, or a percentage of the fees for use. How many get installed would be a different conversation. I'm not talking about free chargers here, just chargers.
So if someone goes to McDonalds for 30 minutes because they have a charger there, mcdonalds would benifit from anything purchased while there + hopefully either a direct percentage for how much time they spent at the charger charging - or a flat fee from the company to have that charger there. If there was a larger demand for chargers at the establishment, they could simply put in more and get more of that money?
Extras at renting places has always cost more. Like I gave the example of -- covered parking, or sometimes just parking.