Clone Wars and Rebels are good though.
The best stories in Star Wars were wiped from canon to make room for the new movies. When it's time for the prequels to be replaced, unfortunately Clone Wars and Rebels will suffer the same fate.
Huh, you know that Lucas didn't like the EU and would have likely either done the same or just completely ignored it, right? Clone Wars already ignored the EU because Lucas didn't like a lot of stuff already established in novels, games and comics.
One example is the name "Korriban" for the Sith planet which he decided should be called "Moraband" instead or just the entire story of the Mandalorians and the Nightsisters.
They did the right choice (and the only reason Lucas didn't is probably because he only cares about the movies and later the CGI cartoon), good or not most sequel stories just didn't fit with the prequels, even less with what Lucas intended about the Force and its implications. Though seeing what stupidity they would invent to try and fit any new movies Lucas would have made into the old books would have been funny. "Hey, this Kira girl who's Luke's apprentice (*), should we say that she helped with the war with the Yuzhan Woong? Or did the training happen later? Did Luke become a hermit before or after the new Jedi council was founded or it's after he disbanded it?"
(*) part of the original treatment by Lucas later recicled for TLJ.