Potato crisps (and similar snacks such as cheese twisties and corn chips, which I will refer to blanketly as crisps) are often greasy or otherwise messy to eat without utensils and other tools. Sure, you could just decide to not eat them while doing your term paper or playing videogames, or you could just suck it up and resign to the completely avoidable fate of getting your keyboard, mice, and books covered with food grease. Or, you could actually use a practical solution.
Chopsticks are long and can reach deep into the bag. They’re nimble and have the ability to pick up large crisps, or bunches of various-sized crisps as needed. They make minimal surface contact with the food, but even if the ends get greasy with seasoning, simply run a single segment of toilet paper down the length of the chopsticks twice per stick (assuming you use smooth reusable chopsticks). Now, they’re clean enough to rest back down to be used again for the next bag.
Chopsticks are of course not just limited to crisps and your more “traditional chopstick foods” such as ramen and dumplings. They’re great for anything else bite-sized: potato chips, chicken nuggets, Turkish pide, and sometimes even chicken wings (although those tend to be a lot more challenging to clean up around the bone), and many others are completely practical to eat with chopsticks.
Other solutions certainly exist and can also be effective (usually depending on the nature of the snack). But for me, although it can look a bit silly, nothing beats the fine control, swiftness, and cleanliness of chopsticks.