As a German I may tune in here. You are right, the Schnitzel was of Austrian origin. You still get the best there and in southern Germany. Cooking Schnitzel migrated north after WW2 predominantly and became a common German dish with many variations. He word “Schnitzel” means something like “snippet”. The basic recipe: Take a thin slice of meat, less than .4” thick. Spice with salt and pepper. Cover with wheat flour. Dip it in a beaten egg. Then in bread crumbs. Fry in a pan with a lot of hot fat, traditionally lard.
Wiener Schnitzel is traditionally served with a slice of lemon and potato salad, but now often with pmmes frites = chips = French fries. By law only a Schnitzel made of veal may be advertised as “Wiener Schnitzel”. Schnitzel made from other meat, pork, turkey or chicken, must be described as , fi, “Schweineschnitzel Wiener Art” = pork snippet Vienna style.
Variations, most often pork:
Jägerschnitzel = hunter style, covered with mushrooms and gravy.
Zigeunerschnitzel = gipsy style with chilies
Schnitzel a la Holstein is covered with a fried egg
And many more….