I don't recall seeing any "public bathrooms" in either of our nearby downtown cities. When I worked retail in one of them, we had customers coming in periodically to use our bathroom. You just had to pick a store and go in and see if they had one for the public. I just assumed this was normal, though in retrospect I suppose a large, properly ADA compliant public bathroom would have been nice ot have downtown. I don't think you could find a store bathroom anywhere in either downtown that you could get a wheelchair into.
You'll have to bring this up with the city council I suppose.
Also, some customers are complete retards. We had a water leak in our basement from the plumbing next door due to some idiot customer next door changing their baby's diaper AND FLUSHING IT. Took them a few hours to drill it out with an auger bit, cost the neighboring store about $300. They were considering closing that restroom to the public as a result. There were even signs on the door saying don't try to flush a pad or a diaper. (the store was a housewares knicknacks so many of the customers were moms with strollers in tow, and this was not their first encounter with a diaper plugging a toilet, this one just happened to make it almost to the street before lodging in the pipe)