That's not curiosity, that's trying to get a reward through randomness. Loot boxes are like being hungry, going to your kitchen, and picking 3 random ingredients to combine. The mayonnaise, raw onion, and ice cube soup is not so good. So you try again. Eventually you land on cooked spaghetti, butter, and cheese. This encourages you to keep trying.
Curiosity is more like scrolling on social media. You know there have been interesting things there before, so you keep looking for more interesting things.