> When storing passkeys in a password manager like Bitwardenor KeePassXC, you end up fighting the platform

Very odd. I use passkeys extensively with BitWarden and I love it to the point where it's my preferred way of securing things at this point.

The fact that the website presents the question to BitWarden in a structured way (what website, what username) means that I never fight with selecting the right account to get the password for (because I commonly have multiple accounts for a single site) and it generally makes the login flow much smoother.

Environment is MacOS with Brave/Firefox + iOS.