I bought a couple of yubikeys but haven't fully implemented yet. When 1password has full support for using a security key in place of a passphrase, I will consider using them as my primary unlock method.
I have to say that the Google Titan appears to be better bang for your buck than yubikeys. The FIDO2 yubikey is $55 which is pretty pricey considering you will probably want multiple. I'd be really curious if there's a strong argument against using the Google keys.