Passkeys are built on the FIDO2 standard (CTAP2 + WebAuthn standards). They remove the shared secret, stop phishing at the source, and make credential-stuffing useless.
But adoption is still low, and interoperability between Apple, Google, and Microsoft isn’t seamless.
I broke down how passkeys work, their strengths, and what’s still missing
How do you currently store your passwords? I would also consider that a third party with an adittional atack surface if you are considering the passkey location one.
Also your argument
is faulty. That is because passkeys exist in part to mitigate those atack vectors. Mitm, a compromised browser or client, etc. is less of an issue with passkeys. The information transmitted during an authentication can not be reused on another authentication attempt.
I don’t agree on passkeys complicating things either. For me the authentication-flow is not more complicated then KeePasses autofill.
Assuming one can be ‘tech savy’ enough to not fall for fishing is bad. There are quite advanced attacks or you might even just be tired one day and do something stupid by accident.
You don’t expext the user to ‘implement’ mfa or biometrics. You expect them to use it. And most places where a novice would store passkeys don’t just expect but enforce it. It is also way simpler to set up biometrics on one device compared to keeping with a good password strategy.