As a Xerathmain, i am never doing most damage in the game anymore

I simply cant compete with the ADC anymore. In previous seasons, Xerath did the most damage because

• He has poke, so he is doing damage when nobody else is. These days ADCs have though.
• AOE damage, which was huge from the midgame, and still a large source of damage lategame. But as ADCs doesn't have to itemize lifesteal or defensive items, because Warlords Bloodlust and Ardent Censor, Xerath simply can't compete.
• Its very hard for either ADC to die. Even if i hit them with a full combo on Xerath, they get a shield and after 2 seconds they are back to full HP. If Xerath is hit by 2 ADC shots, he's out of the fight if he's not dead. The enemy mid has same problem

Another factor is tanks, which Xerath can barely scratch, and the ADC can melt. This is IMO fine and how the game should be. But the other things should be fixed.