Why is Vaynes range so long?

When she was released she had the lowest range in the game of any adc, it was the primary factor that was supposed to balance her overloaded kit. Now she has some of the highest in the the game.

Only Caitlyn, Ash, and Varus out range her by default. Jinx, Tristana, Kog, and Twitch can sometimes out ranger her. Everyone else is either tied with her or less. I feel like she should have 500 or like Lucian or Sivir given how many tools she has to avoid damage and disengage in her kit.