We first need to make it easy for the unbanked to get affordable access to banking services before we could ever consider going cashless.
while it must suck for people who don't have $500 in income a month to wave banking fees of $10/month (those are Wells Fargo's rules, YMMV), the only two obvious solutions are bad. The govt shouldn't be able to force other entities to do it and everyone knows that if the govt got in the job of "Banking for Poors" that it would be a slow and sh**tty service for the poors and cost the rest of us $45B year.
As for the OP, if sellers want to go cashless and their customers don't care, they should be able to do that....the govt shouldn't force it upon them. On the other hand, the seller wants to keep using cash, and their consumers are fine with that, the govt shouldn't force them to go cashless. As always, the govt shouldn't be sticking their dick into voluntary trade between people who want to trade.