Arena blocking progress.
For months players told you they were blocked by the arena for the arbiter quest.
You fixed the problem by putting in bots and the pve players were unlocked (you made a lot of happy people who thought about stopping the game and were re-motivated), while leaving the platinum to players who want a challenge.
And now you're back up with team arena quests.
Everyone (except the whales) will get stuck again because it's going to be like before.
Because arena champions are not balanced. If we haven't had the chance to have the cheate champions, we can't progress.
We end up with classic platinum arena players from the silver.
Either your game is too successful and you do not know how to manage it or you have to resize the arenas and offer a workaround for these # @ [# of quests
Edited