While usernames offer a layer of privacy, they are often more difficult to remember than email addresses or phone numbers, especially if they're not frequently used. This can result in failed login attempts and, eventually, user frustration or even account abandonment.

By offering a variety of login options such as email, phone number, or even social media accounts, you give users the flexibility to choose the method most convenient for them. This reduces friction, improves user satisfaction, and helps retain users in the long run.^[1]

Including an option to log in via a username is still valuable, but it should be just that— an option, not a requirement.