I don't think this will be happening in my stores in my country considering the hatred being shown by the government over the crypto currencies. i wonder when that time will come when bitcoin will be accepted in every store?
I am optimistic about it though, it will start from smaller stores and gradually move to bigger market places. However if some crypto project brings in more promotional ideas on spending their coin to buy grocery - then that can be another impetus to the growth of crypto locally. At present I can spend my bitcoins to buy giftcard and redeem them on a grocery app and use the wallet balance to buy my stuff, but I would like streamlined approach as we can spend fiat.
Every government will not be here forever, so have patience and optimism, good days will come but we have to remain prepared.