My honest opinion on the Native civs about why they’re not that popular is because the Lakota and Hauds, specifically, are basically just Euro Lite reskins. When you play them, you don’t really feel like you’ve got anything to do with those cultures, you’re just playing unusually aggressive European civs that happen to have a Plaza.
The Aztes have a unique army and unique strengths/weaknesses they only really share with the Incans. The Hauds and Lakota, on the other hand, just play like really 1-dimensional Euro civs that have been reskinned to appear Native American.
woops, didn’t mean to finish there
The likeability of the Plaza, from the perspective of the player, likely has very little to do with why the Hauds and Lakota are so underplayed/unliked when the Aztecs and Incans are - the problem is an issue of diversity, and the Hauds and Lakota just aren’t.
From a gameplay design perspective, you can realistically make just about any mechanic fun to play - the fact that the Incans and Aztecs are played and liked decently should be proof enough that the Plaza likely has nothing to do with the issues behind the Hauds and Lakota.
Considering how different the Hauds and Lakota are from the two more southern civs, it seems like now would be a good time to remake them with a different core mechanic, make them unique civs, and this time around, make the effort to make them unique and diverse instead of just Euro Lite reskins.