Oh yeah it was heinous. They surgically removed every character flaw and scrap of growth from every single main character. Instead of Katara becoming a master waterbender through sheer determination and force of will convincing Pakki to train her, she just becomes a master water bender off screen with no real training. Sokka’s ego and fragile masculinity was removed so he’s just competent, respectable goofball from the outset with no growing to do whatsoever. Aang isn’t a fun loving kid struggling to grapple with the weight of becoming the avatar and dealing with the guilt of running away from his responsibilities. Instead he just gets right with the program and has zero internal conflict because in the Netflix show they made it so he didn’t run away from home, he only got caught in the storm by a stroke of bad luck while out of a leisure flight to clear his head. Suki isn’t an intelligent and skilled warrior who organically bonds with Sokka after his growth from backwater jerkoff to humble and honest man, she just sees the guy naked and goes google eyes over him because he’s hot. Zuko isn’t banished for refusing to fight his father, he’s just banished for fighting and losing.

There’s a more in depth video on this on YouTube that Drew Gooden made where he makes the excellent point that Netflix removed every internal conflict and character flaw of each character and turned them all into perfect Mary Sues with no growing to do or conflict to resolve. They’re just one dimensional stand-ins for the original characters. Theres a reason the shows creators no longer wanted to be associated with the adaptation. All Netflix wanted the IP for was the fight scenes. Which are admittedly pretty rad in the Netflix show. But they weren’t interested in the characters of the show or what the show was trying to say.