FIDO traded off convenience for security, and is incrementally building back usability features to what will hopefully be a more secure world. In particular, I'd be rather concerned about using passwords in most of the scenarios you describe where the OS is adversarial.

The FIDO Alliance made an announcement last week where major vendors commit to expanding support for multi-device FIDO credentials ("Passkeys") and using a phone as a roaming authenticator (This is admittedly another device). Both of which significantly mitigate your concerns without any security tradeoffs. See https://fidoalliance.org/apple-google-and-microsoft-commit-t...

How exactly are you bringing your "secure" passwords to the devices you mentioned? If the answer is "install and sync a password manager", that's something my mom will never do (short of having Chrome remember her password).

So either the passwords weren't secure, or we're only building for power users, or we're ossifying on the browser password manager (and keeping passwords) as the way to manage credentials.