With all this true dmg, isnt it time to intoduce true armor/mr?

Hey guys. Im really not happy with the actual state of the game. In my opinion there is just too kuch dmg, especially every champ today, gets a possibility to deal true dmg. So with the Deaths Dance buff, and the possibility to heal by true dmg, ive had an idea to bring tanks back into the game, or lets better say, to give them a counterplay possibility. How would it be to introduce an item, that has similar stats to deadmans plat, but separtes the armor in 30 Armor/30Mr. The passive would be to negate 15% (+0,5% per Level) of all incomming true dmg. I dont know how much it should cost, but im open for Suggestions. What do you think about the overall idea?