Sort:  

Discord seems to do it well. You see me as "mattclarke" there; when I'm actually mattclarke#6202.
Perhaps communities could be beerandbbq0002 etc
If I join based on a link in your post it doesn't matter that somebody else has beerandbbq0001.
But yes, it would make URLS untidy.

Yeah the interfaces have long decided on most common url standards for users,
topics on steem... adding communities will be very interesting for sure.