The first one was good but the past two seasons weren't that good to be honest
I didn't care for Korra or the antagonists in the second and third seasons.
Korra has been annoying for all 3 seasons for the most part but at least in the first season, the antagonists were great. Amon and Tarlock to me were the best part and carried that season. Most of the good guys, from Korra, the brothers, Tenzin, etc weren't interesting or just annoying.
Season 2 and 3, Korra and her team were still annoying, and the antagonists, their stories, weren't as interesting or well written.
At least so far this season, Kuvira's development has been well done. And Korra and her team isn't as annoying, save for Bolin.