It definitely is useful, I use it for train tickets, or user QR codes for things such as IKEA, supermarkets, gas stations… It’s quite literally a virtual wallet where you have all your “cards”, but they are QRs.
This way, for example, you don’t have to install every single app to get the QR code that identifies you in every market. You just paste them into this wallet and you are good to go!
NFC payments require a transaction platform and these things are only possible with banks or huge, “trusted” companies like Google/Apple.
Although things might start changing in Europe (for now) with GNU Taler.