This post is a more detailed/in-depth explanation of why a UID system would be useful for future development of swordbattle.io v1 and v2 (Summary of player id number, by @ManagePasswords.)
Pros:
- Easier Player Lookup
- Stops Dupe Usernames (if possible.)
- Shows Who Signed Up First, Last, etc.
The problem is that there is already a database with a large number of existing users and it would be difficult for the programmer to ensure that all those users get the correct UID.