adc are too tanky

late game it is imposible to kill an adc.They are too tanky cuz they have bloodthirster and guardian angel.And if they have like a leona or an alistart to support tham they are thankier than most tanks.Not even assasins can deal any real dmg to them.And i see riot is trying to bring back the new infinity edge back into the game...Why.Adc already dominate all games.When the new items for adcs arrive we can say bye bye to toplane ,midlane,jg carry.Nope the only true carry is the adc.And there is another problem.All adcs are viable.