Have you seen or used a web application that suggests “Sign in with Google” or “Sign in with Apple”? Did your eyes skip over that and head to the familiar comfort of “create new account” while you tried to remember a unique password based probably on your cat and your birthday? After all, why would you sign into “random-app” with “gmail”? Well, let me explain. The tldr is “if you do this, you are more secure, and its simpler for you, you are giving nothing up”. The longer is, well,. check the short video.