I use private keys but store them on a Yubikey. In OpenPGP format, not using Fido2 at present. I use OpenPGP for other stuff too like my password manager so I'm

I use private keys but store them on a Yubikey. In OpenPGP format, not using Fido2 at present. I use OpenPGP for other stuff too like my password manager so I'm not ready to move to fido. But certificates - no. I don't see the need for this in my home environment. In my opinion it only makes sense if you have a PKI, in which case you already have the whole CA scenario covered.