It's not clear who 'invented' the chip (aka the French fry and the pomme frite). Many countries lay claim to being the first, but it's possible that cutting potatoes into long, slender pieces and deep-frying them is a method that people in several parts of the world came up with independently, because it is fast and efficient, needing little fuel.
What is clear, though, is that they're extremely popular, even if there are wildly varying ideas on what makes the perfect fried potato. Some people like them matchstick thin and fried until they're crisp throughout while others prefer big, fat chips that are crisp on the outside and soft within. Should they be cooked in oil, animal fat (duck fat is currently popular) or - horrors! - should they be oven fries? What potatoes work best? Then there are arguments about what they should be served with - salt only? Ketchup, vinegar or mayonnaise? Gravy and cheese curds?
While making fries is easy, making good ones is not. Most people agree that no matter the style, the fry should have a crisp exterior. The problem is that potatoes are moist, and where you have moisture, you have sogginess. When the raw potato is dropped into the hot fat, it crisps up the exterior, but the crispness is lost because the moisture from within the potato creates steam, which softens the crust.
Some cooks say the potatoes should be simmered in water until they're almost cooked, others advocate soaking the raw potatoes in ice water. Then there are Heston Blumenthal's triple-cooked fries - blanched then frozen, fried then frozen, then fried again - which can be time consuming. Joel Robuchon's cold-oil method involves slicing the potatoes, patting them dry, then placing them in a pan of room-temperature oil and turning on the heat. With this method, which takes about 20 minutes, the potatoes cook evenly, and by the time they reach normal frying temperature (about 180 degrees Celsius), the exterior is crisp and stays crisp. This isn't really feasible for restaurants because it takes too long, and they'd need to start with cool oil each time.
With so much to consider, it's no wonder so many restaurant rely on frozen fries.