Why wouldn't gas stations just start putting in EV charging stations?

I mean, I suppose it's possible there's some level of regulatory hurdle I'm not aware of, but it would seem to be a fairly obvious combination. Hell, AIUI most EV chargers still take longer than a gas pump does to "fill up" a car, so that would make it even more likely for the driver (and passengers if present) to hang about in the convenience store for longer and buy some of the stuff that actually makes the place money.