Since when were ad carries TOO dominant? Most important role? arguably yes. Late game they are clearly the best (I won't argue with that), but they also take the longest amount of time to get to late game. Unless fed, an adc has next to no chance of killing anybody 1v1 early or mid game. They remain squishy all game and require HEAVY amounts of positioning. The increase in armor is more for top lane in my opinion. Far too often, people would buy ninja tabi and chain vest (around a 2k investment) and your opponent could not even touch you.