Why is vayne's the highest adc winrate past 35 min?

Because no matter how tough you are, Vayne WILL kill you if she shoots you enough. Jinx and Tristana at least can have trouble with high-armor tanks and fighters, but there is no surviving a Vayne's damage.

Got a Sion with 6k health and 500 armor? Sorry, % max health true damage!

Because Vayne is still the hardest scalling AD carry in the game simply due to her W.

The other late game hyper carries usually explode in 1 second if jumped on, Vayne can kite for days due to the low CD on her Q and stealth from ult. The only real weakness she has late game is she is 100% single target damage. Meaning if she can't focus on one target, her damage goes down a large amount.

Vayne is the classic hyper carry back before all this nonsense happened I guess she's still way up there

Because vayne has the worst ADC winrate under 35 minutes besides twitch and urgot?

have you read her the description of her abilities

She's free this week, so maybe enough people are playing here to boost her winrate if it went up this past 50 mins

All her power is stored in the right click. No need for skill just let the passives do the work.

Because vayne has the highest dps against any remotely tanky opponents endgame. Some ADCs can have trouble doing much endgame when the enemy team is really tanky and you can barely hurt them much before the fight is essentially lost. Vayne can just wreck even a very tanky frontline.

I'm glad to hear of this actually. It means vayne still has a niche :)