I know exactly what they should do for the game to be 100x more fun. Ofc they won't listen at first and then slowly implement my ideas as they realise.

New 86 arcanes: very high base stats, so high that we don't need any damage buffing proc. Just make Elite of new maps extremely tanky and the proc of new weapons will have % health damage. The domain constantly cleanses your damage so your stupid 10x damage stuff don't work anymore. Just raw procs with creative ideas (stun, dot, health leech, damage resistance etc).
Make new arcane sets that give you new skills when fully equipped, these new skills won't have masteries but will be effected by unique awakes in weapons. Go try it instead of spamming a million vanities every event... People will actually start opening locks again to get all the different arcane sets.