obsolete builds vs conditional builds

ok so ive come to understand that certain builds are from certain seasons, EX: tank warwick, Tank teemo, Tank raka ect. however what ive seen is that those builds are very conditional vs the champions and items they were used to counter when they first appeared. I understand that ill get hate for saying this but some builds are very obsolete on certain champions because of either A. their kit or B. a major change to the champions or items they were made to counter, lets use warwick as an example for situation A and B

Warwick has built in lifesteal not a % just a flat number, now compare this to nasus who gets % lifesteal and you will quickly see a difference between a tank WW and a tank nasus. next WW's only other healing ability scales off of AP and very well I might add however WW cant fully benefit from this without taking a big hit to his overall damage or defence, lastly his speed boost is short compared to what is needed to sustain himself in a fight vs someone with either higher health or more lifesteal. now for situation B

Tank WW was made to counter Lane opponents not prowl the jungle, sure with his ult a tanky ww can get his team a kill but he wont net much besides an assist and in lane its even harder since his likely lane opponent will either build bruiser or counter tank, which makes WW rely on his jungle more than normal. lastly with the introduction of the two last whisper items tank WW is harder to pull off because the reduction of armor coupled with his own weak lifesteal makes him a prime target for ganks and ambushes by the enemy team.

As always thoughts and comments (id prefer nothing negative but I expect it nonetheless) Bones [slayer-jinx-wink]