I've had a great experience with 1Password + Passkeys [0]. With 1Password I can sync my Passkeys between my devices, and it pops up with a notification when I can use a Passkey to login which is handy. I'm not really sure how to use Passkeys on my iPhone with 1Password, but I'm sure that'll come as Passkeys gain traction.
1Password has a directory [1] of sites that have Passkey support, so one day I moved over those accounts.
1Password has a directory [1] of sites that have Passkey support, so one day I moved over those accounts.
[0]: https://1password.com/product/passkeys
[1]: https://passkeys.directory/