Are cinema operators still doing well today?

In times of Netflix & Co, or Mind 50%, rather more that you can foil the ticket sales to the lender?

Still many people go to the cinema. And so much they had to pay back then

No, cinemas, and not just the small ones, have problems and are slowly dying out: https://www.sueddeutsche.de/muenchen/kino-dokumentarfilm-scala-adieu-1.4374478

Whether they will disappear altogether, I can't say.

They sell not only the movie, but also popcorn, ice cream, etc.

A visit to the cinema is (in the appropriate cinemas) a small event. It's not the same as watching a movie at home.