A handful of restaurants which definitely can't afford the amount of people working there and the interior. They always operate the same way: the food doesn't taste good, expensive interior and (many) more personnel than customers.
Unless they all have a philanthropist millionaire as a sponsor, I suspect they launder money. Apparently this is quite common in Germany because hard cash is still common here. Even large sums of money.
A lot of food places, particularly eat-in restaurants, are just perpetually struggling. Half the staff are on minimal pay, or the owner's friends and family helping out. They struggle and lose money for a few years before finally folding. A regular who has no idea about the industry buys the place and keeps much of it the same because they always loved it. The process repeats.