This is why legendary powers were always a bad idea. They nerf the skill to put the power on the items and never have any regard for some sort of linear balance. You either have a broken skill or the skill sucks unless you have some item.
Even in D3 the entire Wizard classes defense was put onto a single ring. 80% damage reduction. You just can’t compete without it.
Now it’s even more of a nightmare. You see a legendary power and have to check every single piece of gear you have to see if you already have it on one of them and juggle trying to get every power on your character because it’s a mess.