FIDO does some dirty things: >FIDO requires an attestation private key, which must be shared between a batch of at least 100,000 security keys. Using a DIY or cli app solution (application running on the host) will likely mean you'll be generating that private key yourself, this makes you identifiable across registrations. >Some sites (Cloudflare) may reject the use of attestation keys which are not found on the Fido…
For consumer scenarios, attestation is often not a requirement. In that case, FIDO offers the "none" and "self" attestation modes. None conveys no attestation. Self attestation involves a per-website key pair. Either of these modes are privacy and DIY friendly.