That's what I was thinking. I've been eating sour cream and fries since I was in high school working in fast food.
To tell you the true get yourself a plain cheeseburger and put sour cream on that. It is dope. I figured that out making messy ass chili cheeseburgers and I mixed in sour cream. It wasn't long before I figured out meat, cheese, and sour cream go very well together.
It's pretty common in Canada to be able to order fries with sour cream, green onion, tomatoes, and cheese/queso. (It's the best thing on taco bells menu and they don't even have it state-side)
That being said fries are way greasier than a baked potato, and they are better suited to more acidic condiments (ketchup, malt vinegar, etc)
Unironically my two favorite sauces for fries. I attribute a not insignificant portion of my weight gain pre-COVID on slathering cafeteria fries with too much mayo.
Also on the list, any wildcard + Fries.
Carne Asada Fries
Brisket Fries
Fish and Chips (malt vinegar fries with a side of fried fish)
Gyro Fries
Poutine (Gravy and cheese curds on fries)
Hashbrown Fries (Fries with whatever you usually put in hashbrowns)
Sausage Gravy Fries
Kimchi Fries (although if the Kimchi "pancake" is on offer, get that)
The list goes on. It's almost easier to list things you wouldn't want fries with and even then I'm sure some maniac would order fries under Sashimi.
In Japan, I had fries with chili sauce and sour cream at an acquaintance's restaurant. I think she picked up the recipe or its inspiration from SE Asia.
Your body requires a certain amount of carbs protein and fat and you are subconsciously drawn to foods that have the proper proportions of these three items.
Potatoes do not inherently have much fat or protein so we add things like sour cream and butter because they are high in fat and then we eat them with steak for protein.
French fries on the other hand is bathed in pure Oil making them really high in fat fulfilling two of our bodies basic needs fat and carbs, we then eat them with burgers that are high in protein. The ketchup has little to do with this specifically however there is a valid reason ketchup is full of citrus acids an acid commonly found in fresh fruits deceiving your brain into thinking you’re eating a healthy delicious fresh fruit instead of a starch filled oil drenched root.
I'm from the deep south and over here we don't call them french fries. We call them American fries, or just fries. French fries are actually a kind of crisp shaped like fries.