Burgers were invented in America.
Now sure, the Hamburger is named after Hamburg in Germany. However, the German version is actually the Hamburg steak. In other words, the meat patty. And a patty does not a burger make.
America was the country that put the bun on the hamburger. This, in drag’s opinion, is when the Hamburg steak became the “burger”. A new word, losing the ham and becoming what would be translated from German as “The people’s meal”. An apt description for the American burger.
In Germany it is just some cheap, nondescript food. That’s why the origins are not really documented in history.
Americans made a weird cult out of it. They may do so if they like. :)