Two factor auth - some physical thing you carry around with you to authenticate with systems - is the very definition of decreasing usability in order to increase security.
To clarify, do you mean usability as "how easy is it for an end user to perform X?" I feel in general, adding security to a system without security does decrease usability.
I think focusing on "relative usability" is important too. IMO it should be able to increase relative usability AND security.
For instance, I find unlocking my phone and paying with apple pay is easier to use than taking out my wallet and paying with a card. Having my credit card information encrypted on the phone makes it harder for a thief to access, when compared to gaining physical access to the credit card.
I also use a yuibkey to store cryptographic secrets.
Generally I leave it plugged into my laptop, so it does not add inconvenience to me in using it. Before I had to type in a long password to decrypt my SSH key. Now it's stored on a YubiKey, protected by a shorter PIN, and requires a physical touch to perform cryptographic operations. By moving cryptographic secrets from a system with a large attack service (the laptop) to a device which requires physical access and has a smaller attack service(the yubikey), I find the system is easier to use, while increasing security.
One could argue a lack of security can lead to a decreases usability. Ex, a system under a successful DoS attack makes the system not very useable. I digress though, as I do not believe this is what you were getting at.
Using a card as auth is not 2FA. I've hated some 2FA methods I've had to use (phone apps, RSA tokens), but when your auth method is just a yubikey or a key card, the usability experience is pretty excellent.
I think they’re referring to passwordless login with physical keys. One unphishable factor that can’t be brute-forced or cloned and doesn’t require typing and password management.
