@Naughtylus we use usernames/passwords, because they are still the most secure method.
Looking at the app description of SQRL there, it seems it is also nothing more than "authenticate with this app/device" (a PGP key pair would be the same).
I.e. that again is basically just FIDO #U2F, which is used as #2A. I.e. "additional to password authenticate with some crypto, which proves a device belongs to you".
The thing passwords provide is that if your device is stolen or hacked, you still need…