I know that they limit the amount of legendaries in the game so that everyone can't just be running around with a full team of legendaries, I have an idea that maybe you could limit the amount of legendaries in another way? like limiting the amount of legendaries a person can have in their teams (if the user has the maximum number of 3 the Legendaries / Mythical Pokemon would be sent to the box for example and if a Legendary / Mythical Pokemon is killed it will be back when you come back to the area) I am not expecting it to change from the way it is, I just want vgc to maybe exist or some unique battle other than "You can use UU pokemon and 2 of them can be OU" for fan made tournaments. again, I am not expecting it to change from the way it is, I just want some more variety on doubles formats and maybe singles too.
Edit: I only know from other people who said: only one person can have a specific legendary and no-one else is unless he's beaten by someone stronger or has it enough time for the legendary to leave the team