It's helpful to have predictable names. Imagine you have to @ someone or add them on a code review by name or send them a chat by name. @fruitloops123 is a lot

It's helpful to have predictable names. Imagine you have to @ someone or add them on a code review by name or send them a chat by name. @fruitloops123 is a lot harder to remember than @mark[Teamname] or @marklastname. When you are large enough first names no longer work.