If Bitcoin is your currency by choice everything else is just foreign exchange. no different than swiping your fiat card at a store when travelling. You pay in your currency, merchant receives their currency. It's that simple.
Discussion
Getting a fiat card is not at all simple
And comes with huge privacy risks
Granted, if you are one of the privilege few who can have (and remain blind to the risks of having) a fiat card then yeah I guess bitcoin backed makes some kind of sense
But it's like arguing the difference between telegram, whatsapp, or signal
They all suck
I don't mean fiat cards. I mean Bitcoin enabled debit cards and I've had them since they became a thing. Before that I used to draw fiat for Bitcoin from almost any ATM in Spain thanks to Bit2Me and their partnership with HalCash. You would just sell the BTC to Bit2Me and in return you receive two codes you type into the ATM to take out the money.
I've been paying with Bitcoin almost everywhere for a long long time.