The vayne nerfs are actually exactly what she needs assuming

Riot brings power back to early game adcs in the marksmen update.

Contrary to popular belief Vayne isn't OP because of silver bolts, the knockback, tumble or every other part of her kit people like to rattle off when trying to come up with reasons as to why she's strong.

She's strong because

a) The meta favors her b) Early game adcs aren't strong early anymore c) Blade of the Ruined King smooths out Vayne's power curve

Most people here probably weren't there, but Vayne was actually pretty balanced back in Season 2. She was useless until she got 3 items (not including boots) after which she was a god.

So since Riot can't really nerf Bork because of one champion nor can they really change the meta, they took the right approach by attempting to make it easier to punish her early game. Probably the biggest reason Vayne is popular is because Caitlyn fell of hard in terms of strength and popularity who the very existence of made it risky to pick vayne.

Hopefully the nerf to her early AD (and yes the compensation buff is fair, her late game needs no nerfs) along with bringing early game adcs back with the marskmen update will bring her back to a healthy state.

inb4 downvoted by people who get triggered by "percent max health true damage".

edit: downvotes but no one can tell me why I'm wrong