Almost all global loot (outside of Void Essence) has something called Luck Safe applied to it which makes sure the luck % modifiers attached to a roll scale in a controlled manner. This is to make sure loot percentages for items won’t be modified wildly, making low-drop-chance items trivial to earn. It also ensures any item that is flagged as luck safe is earnable without having any luck modifier (although having a luck modifier improves your chances). Luck Safe in not applied to gathering loot rolls. This means Gathering Luck is required to obtain rare gathering materials. It also means that more Gathering Luck is able to be applied to rolls when you gather with luck.