I think the issue here is that basically all of the wealthy game companies are constantly copying game mechanics from each other that if any of them tried to start litigating over similar games, the whole thing would explode in their face.
Hence why when PlayerUnknown's Battlegrounds tried to sue Epic, they did it in South Korea.
Patent trolls is in general a company whose only reason to exist is to buy our register simple, general patents and sue other companies. There is usually no other business that can explode in their face. That is one of the most dangerous aspect of them.
Hence why when PlayerUnknown's Battlegrounds tried to sue Epic, they did it in South Korea.
Also, FWIW, I found this online: https://www.gamasutra.com/view/news/273935/Texas_court_affir...
(admittedly, that ruling makes sense, game mechanics would need to be patented, not something you copyright)