Lifesteal should have a cap

Lifesteal is just straight out of control. It's flat out insane that an ADC or an assassin or even a bruiser built with full damage can lifesteal half of his health bar back in 1 or 2 sec during the late game. It's even worse if we talk about, for instance, Yasuo, who can bring back almost all his life with one Q + one auto or Graves, who can be hella tank and have a shitton of lifesteal. They can just focus the frontline and hit them during the teamfight because they will melt tanks quickly enough to reach the backline with almost full life and have defensive items to survive the frontline damage easily , unless it's something stupid like a Darius. I think this could be solved applying a cap to lifesteal, whether on the amount of life you can get per auto or limiting how much % lifesteal you can get.