There's no reason not to trust it. It's strictly better than passwords in almost every regard. Of course if you manage your passwords well, you don't get more security with passkeys, because your account is already safe enough. But for someone, who used to write his universal "Johny1987" password on a sticker at his display, passkey provides security and usability benefits.
Passkey is just not supposed to solve all the problems in the world. It's supposed to replace login and password and that's about it. Authentication.
