People who reject in-group socio-economic norms and isolate themselves from their previous in-group may or may not be mentally ill. If they were in one of those cults that programs their members behaviors incessantly, then it's entirely plausible that they became sane and escaped from a community of insane people.
For example, I've met several people who reported the set of symptoms and behaviors you describe - but in their case, 'the game' involved the fact they came from a wealthy extended family whose entire existence revolved around hanging onto their pool of capital and ensuring some rogue family member didn't gain control of the capital, which funded all their connected lives (including this guy, who was able to travel the country and go to music shows solely because of his family-linked trust fund). The game they all played was keeping the family members that controlled the capital happy, rather than going out into the world and finding jobs, making their own money, and being self-sufficient.
There's just not enough information in your post to evaluate whether the example was escaping from a cult or being indoctrinated into another cult, who is sane and who is crazy, etc.
This isn't one of those cases. She had a career and tons of friends and now she's shunned everything. Her family lives in another state and had zero influence on her life.
But we can't do anything because she still knows how to take care of herself and isn't a danger to herself or others. So it's just sad.
For example, I've met several people who reported the set of symptoms and behaviors you describe - but in their case, 'the game' involved the fact they came from a wealthy extended family whose entire existence revolved around hanging onto their pool of capital and ensuring some rogue family member didn't gain control of the capital, which funded all their connected lives (including this guy, who was able to travel the country and go to music shows solely because of his family-linked trust fund). The game they all played was keeping the family members that controlled the capital happy, rather than going out into the world and finding jobs, making their own money, and being self-sufficient.
There's just not enough information in your post to evaluate whether the example was escaping from a cult or being indoctrinated into another cult, who is sane and who is crazy, etc.