And the problem is people stopped paying cash, thus the facility was largely withdrawn. I don’t know what the answer is, but my gut says if cash remains legal tender, businesses should be obliged to accept it as a form of payment.

Otherwise, vote with your wallet wherever possible and prefer those businesses that do accept cash.

And even if they theoretically can serve you, one generally doesn't want to be 'that guy'.

I'm glad the option is still there in most places, but it's clear most people don't actually care for cash (neither do I for that matter, other than as a backup solution).