Juggernaut Rant & Gameplay Suggestion

Okay, so Riot nerfed the shit out of tank Ekko because he got to a point where he dealt a shit ton of damage, was hard to be killed, and had extremely good stick potential. So why is it okay for another champion to have the same qualities and not be balanced because they were made to be that way? In case you are wonder I am talking about all of these tanks in meta that have high survivability and still deal extremely large amounts of damage. The main champion is Darius. He has a built in low cool down heal, high base damage, true damage on resets, and when his passive activates he recieves 200 AD and a high AD scaling bleed that can deal hundreds if not thousands of damage in fights. We also have Irelia, who isn't as prominent as Darius, but still has the same capabilities as tank Ekko. She is highly mobile, has reliable CC, has a lot of damage, is hard to kill or even peel because of her passive, and has great stick potential. Again, why is it that certain hand picked champions get a pass on being too much, while others are dealt with simply because its not their design? I am not saying I want tank Ekko, I am just saying these types of tanky high damage healing champions are not healthy for this game, and shouldn't exist even if they were designed to fulfill such a role. Perhaps lower their healing, lower their damage, and focus more on them being a tank. Or, you could have them be more of a bruiser like Xin Zhao and just nerf how strong they are without a lot of offensive items.