The lack of racial diversity for the empires outside of the Federation makes it feel like somehow only the Federation ever figured out how to work with others. Even problematic caste style situations do not come up enough, let alone just simple variations of races.

The most "diverse" other empire is somehow the Dominion. We know the other empires have other races in them as well. It's such a Federation centric view of the universe and I feel that it reinforced my America centric mindset because the parallels seem so direct to me. We are diverse, everyone else is easily groupable into divided others. Only we are Free. Only we are willing to work together.