This is just an idea, I love WvW and don’t want to take away from it.
What if there was a “Battle Royale” map? It would be server vs server just like WvW, set in a coliseum. It’s big enough for however many people (maybe 50vs50vs50 or 100vs100vs100) there’s no objectives and the only waypoint is on the entry platform for your server (where it kicks you off into the pit after 30secs).
Give people xp, some small amount of karma (in line with earning karma elsewhere), and the same loot as WvW. Your loot goes to the entry platform for your server and you can waypoint back occasionally to pick it up.
It’s literally just a battle royale, because some people don’t need a purpose, they just kill cause they like killing.