One of the bigger problems I see with public chargers is that most people, myself included, park the car on the charger and then leave. They leave for 30 minutes or an hour or a few hours like I do at work. The chargers in airport garages can be "in use" by one car for several days even though the charging is finished in a couple of hours. That is mostly fine right now as there are more chargers than EVs on any given day, but that will eventually change.
I can envision a valet service for charging at high-volume areas that have limited charging capacity. Airports, shopping centers, entertainment areas, dense population areas. Those places where people park their car and then leave for a couple of hours. Then, the $50 fill-up might be worth it, as long as it comes with a car wash, too.