Hmm... why don't they already implement their own authenticator apps, if it's just risk aversion and cargo culting? Again it's totally possible and it already exists.

I currently, exclusively use my Yubikeys as passkeys, and it works everywhere where passkeys are available. So I don't personally see a problem.

What I see is that people complain because of some kind of disagreement that happened between some people on the Internet about the passkey implementation in KeepassXC. And nothing about that materialised.