So what's wrong with Vayne?
I remember just about 2 months ago, a lot of players were complaining that Vayne needs some buffs, that her range sucks, and that she just wasn't a competent ADC. However I see Vayne moreso than any other ADC these days, and she does quite well. Come late game, she seems to be the best ADC available, and even before then, her kit seems very good in comparison to even other ADC's such as Ashe, Graves, Varus, and Miss Fortune.
As far as I know she didn't receive any buffs recently, so what exactly happened? No one's complaining about her anymore.
got buffed. Vayne would almost always rush BoRK, it scales extremely well with her true HP% damage passive.