You have to make sacrifices when itemizing.
Yes would it be better for your damage if you went 
instead of 
against yasuo? Yes, but can you deal damage when you are dead? no.
You have to make sacrifices when itemizing. Will you delay or have to replace a core item to do better in lane? Yes, but depending on the situation it is worth it.
In order to defend yourself better against the enemy you will have to make some sort of change in your normal build path.
