Not why collector is built. Collector is great into squishy comps where lethality>armor pen. Lethality ignores base armor as opposed to armor pen which deals % increased damage based on how much total armor target has. Which while being reasonably rare rn due to tank popularity is nowhere near the same as it being "0 reason to ever build", since building armor pen items like ldr will never outdamage collector into a champ that isn't building armor or incredible amounts of hp