Passkey is some sort of specific unique key to a device allowing to use a pin on a device instead of the password. But which won’t work on another device.
Now I don’t know if that key can be stolen or not, or if it’s really more secure or not, as people have really unsecure pins.
You can still use a 37 character password to protect your passkeys in your pw vault, so it’s not like anyone is forcing you to change.
It’s still a single factor though. The number of times I have had to lecture IT admins that their 64 character passwords was compromised by a keylogger and that they need to move towards MFA is too damn high.
As for your phone, if that’s sufficient for you, go for it.
There are better phones out there.
I have MFA in addition to that pw, yes
That’s news to me. Which other mobile authentication is there besides pin, pattern, facial and fingerprint?
Most phones allow passwords, or at least longer length pin.
My 6 character alphanumeric pin is more secure than your four digit numeric
Even FIDO2 MFA doesn’t protect you from attacks that involve malware running on your machine. If there was a keylogger on their machine then that machine is likely compromised in other ways, and any credentials entered or stored on it should be considered compromised and should be reset.