That's not incorrect, but also not completely correct.
Belgian historian of food, Pierre Leqluercq noted that the first recorded mention of French fries is in a Parisian book in 1775. He traced the history of French fries and found the first recipe of what is a modern-day French fry in a French cookbook from 1795, La cuisinière républicaine.
It was these Parisian fries that inspired Frederic Krieger, a musician from Bavaria who learned how to make these fries in Paris, to take the recipe to Belgium. Once there, he opened his own business and began to sell fries under the name ‘la pomme de terre frite à l’instar de Paris’ which translated to ‘Paris-style fried potatoes.’
source: History Cooperative "The Origin of French Fries."
There's also a story in the July1899 edition of Good Housekeeping that refers to "French fries."
TLDR: Belgium acquired fried potatoes from France via a German.
Back to the topic of struggling chain restaurants, there are some chains who are flourishing because they deliver great service and great food. Some chains are struggling because they don't do that. Mc Donald's problem, in my view, is not with the ingredients but with franchisees who don't prepare the food properly and who sell product that should be tossed. McD's needs to go back to the days of the "blitz." That's where secret shoppers would swarm a restaurant and rate everything from food quality to bathroom cleanliness to whether the bag was folded and presented correctly through the drive-through window. At my store, they would hide out among the crowd in the bus shelter located opposite the drive through. No, I am not making this up. It was a real thing. FWIW, the bags I presented were always folded correctly.