This Weird Vayne Nerf Doesn't Seem to Be Fixing Her Problem

Ok so on the 6.24 pbe, vayne is getting nerfed(who would've thought). But rather than nerfing the ad ratio on her Tumble at_ later_ levels, the ratio is nerfed at earlier levels. To be honest this seems like a pointless nerf to me because it doesn't fix the current problem with Vayne being that her late game damage w/ shivv being too strong. Not only that, but the stealth duration from her ult is being halved down to 0.5 seconds from 1 second. I can kind of understand if this was to nerf the synergy with duskblade, but why nerf the character and not the item. In my opinion, the problem with Vayne was that she was doing too much damage with a cit build as a result from the changes to her tumble from patches 6.15 and 6.17. With all of this said, this isn't me complaining about Vayne but rather just giving an insight as to how we can fix her in the current state of the game. Anyways I'm wondering what anyone else thinks of this change as this brings a lot of salty tears in my eyes.