Some people blame bruisers for the death of tanks, which is false. Though some bruisers are not fun to deal with, tanks are not played because of how garbage MR items are. By late game, Mages have Sorc Shoes, Void Staff, Morellonomicon which cut through MR items like it's nothing. So by late game, you're just a useless sack of shit getting 1 shot while dealing no damage. All of the good tank items are Armor items, all MR items need a straight buff.
You cannot play a tank against Vayne. Her percent health true damage is impossible to deal with as a tank, as her entire kit is toxic. Vayne is incredibly shit design which they try to force on the game for some reason, but this champ that successfully kills an entire class.
The solution to this? Clearly it's buffing her Condemn. Also nerf Conquerer. And Buff Omen.
Not to mention if you have to lane against her in Top lane you can't do anything.
It's way preferable to pick a carry/lane bully and snowball.
Stop acting like buffing tanks damage will do anything against the insane damage in the game.