Notably Discord stopped using that format two years ago, moving to globally unique usernames.
Their stated reason[1] for doing so being:
> This lets you have the same username as someone else as long as you have different discriminators or different case letters. However, this also means you have to remember a set of 4-digit numbers and account for case sensitivity to connect with your friends.
Their stated reason[1] for doing so being:
> This lets you have the same username as someone else as long as you have different discriminators or different case letters. However, this also means you have to remember a set of 4-digit numbers and account for case sensitivity to connect with your friends.
[1]: https://support.discord.com/hc/en-us/articles/12620128861463...