Why is it that Katarina is a melee champ with no cc, slows, utility or anything to offer

Katarina Has nothing to offer for her team (which is normally fine since she's an assassin) but she also has no cc, natural built in sustain, or any form of damage reduction, shield, or anything to protect her and allow her to be the "All in assassin" she's supposed to me. It's like making a melee champion had no ability to get into a fight or stay in a fight.

I'm not asking for anything even though I'd love to see a slow or survivabilty added. I just don't get why so many champs have utility or shield/sustain and an all in melee champion doenst.