I think it's possible that in the future most cryptos will be accepted at supermarkets the same way they accept different different credit cards. The main issue noawadays with cryptos is the scarcity of use in everyday life but this may change soon and then the bubble talkers will all disappear
Its not gonna happen, as long as the fee is this high. Buying a cola, and paying double because of fee, is not something most are willing to do in the long run. Daily shopping is a no go for bitcoin as it is now.