This is a great point. And to respond to the other part of the parent comment about storing "all their credentials with one of the large tech companies" — you don’t even need to do that, if you don’t want to.

Apple just extended their Credential Provider API such that passkeys can now be synced using external providers, meaning password manager apps can save and offer passkeys on iOS, iPadOS, and macOS. So you can choose to sync your passkeys with whatever your favorite password manager is.

See this page: https://developer.apple.com/passkeys/

And Google announced a similar API a month or two ago.

See the section titled "Passkey support for Android apps" on this page: https://developers.google.com/identity/passkeys/supported-en...