Have you been to any bar, store or service center lately? Most are cash only in major cities. They avoid credit card fees and avoid paying taxes too.
There are very few that are actually cash only here. What's more common are $5-10 minimums, either not allowing cards at all under that amount or adding a 25-50c fee if you do use one. I'm not completely cash free as a result since I don't feel like paying extra fees for no reason.