[qayxc]

It's a research paper. Not everything that comes out of research has an immediate real-world application in mind.

Games are just an accessible and easy to replicate context to work in, they're not an end goal or target application.

The research is about AI agents interacting with and creating world models. Such world models could just as well be alien environments - i.e. the kind of stuff an interstellar and even interplanetary probe would need to be able to do, as two-way communication over large distances is impractical.