I feel like a boomer.

I dont want to use google/apple/microsoft for any credential manager because: google is evil; apple has locked me out of my apple id (and lost things like the recordings of conversations with my father during his hospice); microsoft keeps getting worse and more annoying to use.

So ok, I need some credential manager. I used keepass previously... but how do I vet other credential managers? I dont want an online backup. I want my credentials to only be on my computers. So now I gotta learn about which apps are ok, don't have cloud synching, can export files, and be compatible with MacOS.

And I have to learn what is FIDO? Like FICO? why do I need to synch with FIDO? what is it? will it give my credential store to others?

How is this easier or more convenient than a user/pass with 2fa?

I feel like I am going to accidentally leak my credentials and have no way of knowing

> I dont want an online backup. I want my credentials to only be on my computers. So now I gotta learn about which apps are ok, don't have cloud synching

If an "online" password manager uses end-to-end encryption, then the credentials really are only on your computers. The only thing "in the cloud" is encrypted blobs of data being moved around for the purpose of device sync and backup.

This insistence on using local non-syncing password managers is a masochistic exercise in making life difficult for yourself with no security benefit.

In your case it's literally the same "complexity" as user/pass with 2FA. You need something to manage the passkeys, just like you need something to manage your second factor. Everything else you list as a worry is already in play.

FIDO is a standards body which produces specifications used by these systems.