Ease of exchange. I can’t (easily) give you 100 GME to buy a new car. We’d need a particular arrangement which isn’t easy to come by in the current setup.
If anything, cryptocurrencies are becoming more like illiquid equity rather than a currency. I can't exactly go to the store and exchange BTC for milk.
Interestingly, local dispensaries at one point entertained the idea of BTC ATMs to get around the fact that they have no ability to take credit cards due to the illegal state of pot at the federal level, but this was abandoned after a bit because the volatility was too expensive to make this a worthwhile proposition.
What I do is use the virtual crypto wallet in Revolut. Keep money in BTC and when I want to buy something move the exact amount across to the FIAT currency account and tap to pay.
I keep a small float in FIAT so I only do this when it’s the cheaper option.
Interestingly, local dispensaries at one point entertained the idea of BTC ATMs to get around the fact that they have no ability to take credit cards due to the illegal state of pot at the federal level, but this was abandoned after a bit because the volatility was too expensive to make this a worthwhile proposition.