True, but fwiw I wouldn't consider potato to be particularly important in German cuisine. Sure you'll see it used quite a bit, but many of the more iconic dishes don't really need them or can be replaced like with bread dumplings for instance.
Another, more recent, statistic[2] bears this out, 54 kg, and also has surprising (to me) details. Of those 54 kg, fully two-thirds -- 38 kg -- are processed potatoes (the article names potato chips/crisps, ready-to-eat potato salad and, of course, fries) and just 16 kg are "real" fresh potatoes.
Finally, things used to be different[3]: in 1950, the per-capita consumption was 186 kg!
[1] https://landgeist.com/2021/12/21/potato-consumption-in-europ... attributed to FAO
[2] https://www.bmel-statistik.de/ernaehrung/versorgungsbilanzen... German dept. of agriculture
[3] https://www.statista.com/statistics/539799/per-capita-consum... it doesn't say, but I doubt people were eating a lot of potato chips in 1950 Germany
Also notable is that a lot of dishes that seem popular in Germany when I went aren't very common in the US in german-american areas as far as I can tell. Spaetzle is basically just a novelty, and I never see schnitzel per-se, but we do have equivalents like chicken-fried steak. We also basically never use the German name for anything except sauerkraut, bratwurst, and strudels, which to my understanding is because the US heavily de-germanized in WW1.
But a good Rhineland Sauerbraten for example would normally be served with potatoes and a good Bauernomelette demands some crispy fried potato slices as well. Semmelknödel (but also often offered alongside potato dumplings) are a more common sight at special occasions or buffets. Many a young family's weekly rotation features spinach, fried eggs and potato mash alongside fish sticks, fried potatos with fried eggs and onions are a popular hearty lunch or late breakfast, and cooked potatos or mash are the default addition to some meat or sausage to the point a common microwave TV dinner still consists of Nuremberg sausages, sauerkraut and mash.
While the classic northern "Salzkartoffeln" are basically non existent in Swabia, potatoes in general play a big role in traditional Swabian cuisine. Whether its "Schupfnudeln" (finger noodles), as salad, Knödel, fried potatoe slices, Hitzkuchen/Blootz/Dinnete (Pizza with potatoes instead of tomatoe/cheese), Kachelessen/Griebaschnecken/Schlanganger (various potatoe and milk dishes), Gaisburger Marsch (stew), "sour eggs" (potatoes and eggs in a vinegar sauce).
But unfortunately most of those dishes are not really cooked anymore. (For "sour eggs" thats a good thing, this tasteless sour graybrown dish can die in hell for all I care.)
I was happy to discover canned pinto beans at my local supermarket but they were only available in a hot tomato sauce (branded as "chilli beans") - I only just found out the overpriced exotic Italian Wachtelbohnen collecting dust in the shelf next to them are pinto beans too.
Heck, I'm nearly 40 and I've met Germans my age who were intrigued (or put off) by couscous because it's so exotic and they've never tried it before. I've talked to people running kebab joints (Dönerbuden) who said that they stopped offering lamb meat because the Germans didn't buy it and the few Turkish and Arab people who frequented them weren't enough to justify the overhead.
I take it you live in a city. When I lived in Cologne, everyone obviously knew couscous. Rural Germany is a very different place. Granted, this was like 10 years ago but there's a reason we have the saying Was der Bauer nicht kennt, frisst er nicht ("what the peasant doesn't know, he doesn't eat").
Another cultural fact: "Kartoffelferien" (="potato holidays") are still used by some elderly to describe the school holidays around october, because children needed to help with the potato harvest around that time.