Hi, jidanni,
It seems many posts and links here answered your questions and your topic doesn’t really fit ux, as you can see from the category’s description, as the appended username is rather a feature:
If you want to request a per-user setting, which is legitimate, feel free to open a new topic in feature.
But also note that you can easily copy-paste Discourse URLs without your username simply from your browser’s address bar, which is always updated in real time.
You can see that, for example, when you navigate inside a topic: the URL is constantly updated with the current post ID.