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



They were surpassed by password managers and 2fa.
Technically they are the 2fa. The second factor is something you have. I store all my passkeys in my password manager too, so I’m not faulting you, but technically that’s just undoing the second factor, because now my two factors are “two things that are both unlocked by the same one thing I know”. Which is one complicated factor spread across two form fields.
Password managers are a workaround, and broadly speaking the general system is still weak because password managers have relatively low adoption and plenty of people are walking around with poorly managed credentials. Also doesn’t do anything to mitigate a phishing attack, should the user get fooled they will leak a password they care about.
2FA is broad, but I’m wagering you specifically mean TOTP, numbers that change based on a shared secret. Problems there are: -Transcribing the code is a pain -Password managers mitigate that, but the most commonly ‘default’ password managers (e.g. built into the browser) do nothing for them -Still susceptible to phishing, albeit on a shorter time scale
Pub/priv key based tech is the right approach, but passkey does wrap it up with some obnoxious stuff.