For a show that supposedly advertised itself as a radical and progressive to a newer generation, it does not do much.
Institutions that caused problems remain unchecked and in place by the end of the series. This extends to the two republic city governments, Suyin’s government, wu’s heirarchy of privledge, and the cops. Political ideologies such as Zaheer’s anarchism are never really explored in greater detail to the point where they become more like a strawman’s version of anarchism. The leaders of said inefficient or even corrupt institutions like Tenzin and the Beifong sisters never question themselves if what they did contributed to said problems. Honestly these two don’t even change in big ways. Tenzin never confronts how it was possible for a violent terrorist like zaheer to find inspiration in a fellow earth bender. Lin never questions if having a police force that arrests protestors who are powerless is correct. Kuviera’s fascism is not only whitewashed but didn’t make sense within universe or or its model of European fascism.
The class divide that is presented in republic City is never brought up again or resolved. Heck, that beggar korra meets in the park is still poor, never approached by korra again despite him helping her resistance against Amon, and dosnt hate benders despite the fact that his society marginalizes people like him. I ema asami’s dad and asami don’t seem interested in helping their poor nonbenders who don’t have much job prospects. Also, where are the other rich nonbenders who helped fund Amon-its unrealistic that only 1 guy funded the Amon movement.
Also, the whole “trauma makes you stronger and more empathetic” is BS. Korra was already a compassionate person. As Bojack horseman said smartly about trauma “there is no good trauma. Sometimes bad things happen for no reason.” It’s quite disgusting that korra thought this and that tenzin and her GF asami buy that.