Librum now makes a new usb security key that one can use for two-factor authentication. This is made with totally free software; read about it here (https://puri.sm/posts/purism-launches-librem-key-only-security-key-to-offer-tamper-evident-protection/).
Cool. I noted that it's about $59. I personally don't care if it has all Free software, I just want it to be reliable and secure. That's also why I think I'd still get a YubiKey given the choice again, it's been out longer than these newer alternatives and so I think they know their stuff. The other guys are going to be making mistakes likely. I'm sure in a couple of years, they will have worked out any bugs though.