Phil is delusional, but still has a partial grip on reality. He pays enough attention to current events to have some idea on how he is supposed play make believe while still being "mature" enough to show up to events that the character he is pretending to be would go to. In Phil's eyes, he is some kind of latinx anarchist anime heroine, who must defeat the evil Fascists and save the world.
I think the key difference here is that Chris's Dimensional Merge is his way of coping with the fact that his mom (the only person willing to tolerate him) will be dead sooner rather than later, and with her death will come bills he can't pay, followed by him eventually losing the house (along with all of his toys and video games), then being either homeless, put into some kind of institution, becoming a burden on some ween or white knight, or maybe even dying. There is no denying that Chris' life is going to see a sharp decline within the coming decade.
Phil though? Motherfucker is just a step above homeless. Shit, he's been homeless (or so he claims). He's already destroyed any and every relationship he's had. He doesn't have a goddamn thing to lose. Phil could lose literally everything he owns and hardly anything would change in his life. He doesn't need to pretend his problems will magically go away, because he's convinced that he will help solve all of the problems of the world (which are all caused by capitalism, cops, and conservatives).
