It would be cool but I think that depends on the regulation of each country. One of the challenges of cryptocurrency as a form of payment is legality and the government.

Essentially, if it's accepted as means of payment, then it's a payment instrument. Some countries only recognizes cryptocurrency as form of investment and not a legal tender. It could be an issue if you run a mid sized business accepting a cryptocurrency in a country that doesn't recognize it.

I personally wouldn't oppose that. I have used it for so many things in the past, even there was a burger paid with steem/sbd. So, this concept isn't something new but again, regulation remains a challenge.