my point was more general to the unsustainability of public infrastructure in sprawl prone towns.

Outside of the NE corridor of Boston-NYC-Philly-DC, I don't think any other major US city has the density for a high coverage public toilet network.

qualifier City of Boston and SF are fake cities. The real cities of Boston and SF extend far beyond their city boundaries which capture a tiny group of neighborhoods. The real city of Boston would also fail my criterion. Small cities like Portland, Maine do well-ish, but my focus is major cities.