I have 1 question about these bitcoin debit cards? Do they work with all ATM's or the banks have to uppgrade the ATM's software in order to read BTC. I`m sure ATM's, whatever software they use, dont even have the 'BTC' character implemented in their software.
So i`m sure the banks have to do work too to implement this feature.
It's pretty simple. Your BTC debit card provider (ie XAPO, Bit-x, Bitstamp etc) keeps your BTC funds and converts to fiat whenever you want to use the card, therefore you're paying with fiat (but it comes from your BTC deposit). So yes, it works like a regular card and you can pay pretty much everywhere.