Germany and Italy aren't actually neighbors. They are separated by the Alps, a massive climate wall that permanently divided Europe's butter eaters from its olive oil eaters.
Austria and Switzerland sit directly between them atop this mountain range. The peaks block cold northern air from reaching the Mediterranean and trap warm southern air from moving north, creating two entirely different agricultural zones.
North of the Alps, Germany has a continental climate. Before modern supply chains, German farmers had to grow crops that could survive short summers and cold winters, like potatoes, cabbage, rye, and root vegetables. The climate was better suited to raising cattle and pigs than growing oil-producing plants, making butter and lard the default cooking fats.
South of the Alps, Italy enjoys a Mediterranean climate. The long, hot summers and mild winters allow farmers to grow tomatoes, citrus, and durum wheat. Crucially, the climate supports olive trees, making olive oil the foundational cooking fat for almost every dish. The difference in base fats—butter in the north versus olive oil in the south—is the primary reason the two cuisines taste so distinct.
However, the premise that the two cuisines have nothing in common is also false. As you move closer to the Alpine passes connecting Northern Italy to Southern Germany and Austria, the culinary lines blur.
The similarities are most obvious in everyday staples. German Spätzle is a form of fresh egg pasta, functioning much like Italian noodles. In the Italian region of South Tyrol, locals eat Canederli, which are identical to the bread dumplings (Knödel) served with roasts in Bavaria.
The most famous shared dish is the breaded veal cutlet. In Germany and Austria, it is the beloved Wiener Schnitzel. In Northern Italy, it is Cotoletta alla Milanese. Food historians still debate which culture invented the dish and which one copied it, but the preparation is nearly identical. Rather than a hard border where olive oil and tomatoes instantly give way to butter and cabbage, Europe’s food map is a gradient that shifts gradually as you move through the mountain passes.