Interesting analysis.
I felt the show missed an opportunity with the Inaros character (I haven’t read the books). He felt truly cartoonish in his narcissism and pettiness. They could have, and I believe there were hints, shown him as a brilliant revolutionary and military leader that ultimately would fail because he had no vision for a functioning civil society. This might have been a more interesting end for that storyline. In the light of your perspective, coming up with ideas on how the Belt would organize and govern themselves beyond tribalism would have added to the story as well.
I had a similar issue with Black Panther. Wakanda, despite its technological superiority, is still a hereditary monarchy who’s leader can be determined by a duel. This seemed rather unrealistic and condescending to me.