champs without mana shouldnt be able to buy items with mana

ranged champs cant build hydra or steraks melee champs cant build ruunaans why can non mana champs build mana items? its beyond toxic when the enemy garen gets a triforce and can kill anyone 1v1. garen is one of many problem cases, many champs that dont have mana abuse stuff like sheen akali building lichbane is ridiculous. one could argue that the mana is a waste of their gold and come endgame they might not be as strong as if they had spent the gold on something without mana. but i disagree sheen is a big a powerspike and people without mana shouldnt be able to abuse it.