They were not.
Rey was perfect in the first movie. She was a desert dweller who'd, as far as we have any reason to believe, had never flown a spaceship but she's instantly a better pilot than Han Solo, able to repair the Falcon better than him too. Then she uses force powers without being trained and defeats Kylo in a duel, also without training. Then she just gets better and more powerful for no reason in the subsequent movies, kicking Luke Skywalker's butt (again without training) and of course being over the top powerul in the third movie. Boring character who never struggles with anything.
Or Poe? He has no character so hard to say it changed. He was just "the best pilot" which we know because we're told that, and that's about it.
Finn? You could say if anything he regressed, in the first movie he was a weakling who found strength to stand and fight when he knew the odds were bleak (and he was struck down) but then he became dopey comic relief.
Those are the primary characters. I'm curious who you think changed and grew through these movies, other than just getting more powerful inexplicably because the girl power narrative needed one of them to be the most overpowered character ever.