Building tank items is like throwing gold away.
When you build a tank item, you are only getting about 80% of the gold you spent as value. That is assuming your opponents don't have any anti tank. Since most top laners run conqueror, mages getting 40% pen from void staff, adc getting 35% pen from lord dominik regards, and many champions having true damage or % max hp damage, tank items plummet to around 40% value. The best defensive items in the game are
as their protective effects can't be mitigated.
would like a word with you
and they won't be able to touch you. Vs On hit AD champs you can swap Randuins for Thornmail and it's equally good