I noticed that quite a lot of websites are using two pages login model today
e.g. AWS, google, apple etc.
They suggest user to type an account id/email and then navigate to a different place to enter the password. Overall it is just annoying, it makes the process longer and makes it harder using a password manager (as it needs to learn how to populate two forms). Could you help me to understand if it is done for some kind of security reason?