For those of us wanting non-big-tech implementations of WebAuthn/passkeys, there are options for storing passkeys in software, and for storing passkeys in TPMs.

https://github.com/bulwarkid/virtual-fido/

https://github.com/keepassxreboot/keepassxc/pull/8825

https://github.com/psanford/tpm-fido

https://git.kernel.org/pub/scm/linux/kernel/git/jejb/fido2-c...