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.
While I would agree this sounds more secure, I’m always worried about people getting further locked in to Google’s products.
Hopefully this system won’t take accounts “hostage” by requiring you use Chrome to log in to them, but it’s Google, so…
EDIT: I’m wrong, passkeys are stored per-device and can be shared between devices using an open standard. Here’s a video explaining the basics. It addresses my concern at around the 2:50 mark.
Passkey is an open standard. It’s not Google specific.