It dawned on me recently after I see sustain champs that already have built-in heals taking corrupting potions. Junglers have their item restricted to their role. Some items are restricted to champion attack type (Ranged only for Runaan's or Ravenous Hydra for Melee etc.) Why don't we create more class/role restricted items?
There was even the notion of nerfing support items and gold-pers a whole back.. actually multiple times. Why not rebuff them, and restrict gold-per items to supports? Why don't we restrict corrupting/refillable potions to those without built-in sustain? (Or better yet, just remove the item altogether.)