Your GM might also need help understanding why it's bad and unfun for players to constantly lack agency. I don't have any great ideas on how to get that across, but it seems like it might be a key concept. If he thinks that what he's doing is great for y'all just like it is for him, then he's not going to care much about anything you say to the contrary.

Maybe he thinks you get your jollies from fighting for control of the game, so he's just trying to give you the best game possible by providing a good struggle.