What is good UX?
To me, a good UX is any design created to simplify the user's experience and, ultimately, the user's everyday life. One feature that best describes my point of a good UX is the verification code autofill feature.
Two-factor verification (2FA) was created as a safety method to increase the difficulty of users users' accounts; even the user's login information was obtained illegally, as it requires the user to enter a security code through two communication ends.
2FA has been popularized in recent years with the increase of user information leakage, often due to big companies with weak security measures targeted by hackers to obtain and leak significant amounts of user data.
Like many other inventions, 2FA started with a relatively poor user experience. Users often have to go back and forth to copy their code and rewrite it on the intended application that users wish to proceed with. The frustrating process hurts the user to continue using 2FA and could hurt the product of what the user wishes to proceed with.
The introduction of verification codes for 2FA being auto-filled has solved a significant issue of bad user experience: the annoying process of copying and pasting the code through two software. It is a beneficial feature that helps keep the user's account safe while reducing the time of obtaining the security code. And that's why the introduction of 2FA autofill is a good UX.