Yubikey can be used as passkey atorage, I do it on Linux desktop/laptop with passkeys. It requires touching it (but no biometrics). I just couldn't make Android ask my hardware device, it wants to handle passkeys by itself.

It's false that passkeys cover biometrics. They cover password + OTP (aka 2FA aka MFA, although BestBuy requires OTP even after logging in with a passkey).