I mean yeah, I can’t disagree that in the majority of episodes have happy endings for the Rebels, but it’s not like they have any setbacks. The Grand Inquisitor is pretty effective at hunting down and overpowering Kanan and Ezra in season 1; Vader expertly manipulates them into stealing a tracked shuttle and then destroying most of Phoenix Squadron; Ezra nearly gets everyone killed in Steps into Shadow and has to deal with his failures; Thrawn discovers the identity of Kallus despite his best efforts and uses Kallus to track them to Atollon and destroy most of their ships; the Rebel Alliance have a squadron of x-wings attack the Tie Defender factory and the entire squadron is destroyed. The show had setbacks for the main characters, it just knew when best to place them.
Sure, for a series set in the “dark times” as Obi-wan calls them, there are a lot of happy endings. But as Dave Filoni said Star Wars is meant to inspire a good feeling. I wouldn’t have it any other way.
I’m not going to talk about Rebels any more though, we’re been sidetracking this thread for a while now…