I really like GRC's Secure Quick Reliable Login (SQRL). It's older than most examples but basically just the open version of the prompt on your phone. Authentication requests are made for a specific domain and sent back to that domain only. So much more phishing resistance than has been typical, similar to passkeys. It's as seamless as scanning any QR code with a phone, or it integrates with a browser or local password manager/daemon. The prompts on the phone show you the unobfuscated domain name of what generated the QR code/auth request and if it's never been used before like a phishing site, it'll only offer user registration (usually with one-click).

The backups of your credentials are just QR codes and can be printed on standard printer paper.

It is used internally at a midsize organization for their internal systems authentication. Way less hassle than the Microsoft authenticator, no added hardware like a passkey.