can FIDO2 be implemented for day-to-day use right now, such as email access? sms 2FA and authenticator are built-in to most applications, so it makes it easy to use.
and how do you do estate planning? I'd like to give my family access to all of my private keys for everything when I pass.
It’s built in to Safari, Chrome, Edge and other browsers, apps can easily integrate with system libraries for Windows Hello or Touch ID as they would anyway.
As for estate planning, set up a spare key that you can keep at a relative’s place, or add others’ accounts to your “Family” in Google/Microsoft/Apple/etc. Either they have their own keys and the company is aware of the handover or they have a copy of yours — such as you logging in on their device or keeping a FIDO2 key at their house and they can pretend to be you. A service like 1Password Family could also be of use here.
and how do you do estate planning? I'd like to give my family access to all of my private keys for everything when I pass.