how does GPT make money?

I had high hopes for Zero and the build-up in the finale was cool but I couldn't help but feel like "that's it?" There's so many unexplained loose threads that have gone unaddressed and yes I know they'll get addressed in Azure but I think Sky 1 did a much better job of using all the pieces on the board that they set before their finale chapters and utilizing them all meaningfully. I'm underwhelmed

on a long enough timeline, every country will get a nuclear bomb

Are you supposed to open with Carty, outro into Cia, outro to Aerover, and then outro back to Carty? I'm not sure if I have a full understanding, thanks to any kind knowledgable anon in advance