Ichigo gets a lot of shit (typically from outside of the Bleach fandom) for being a character whose wants/goals never change from beginning to end of his series. He always wants to protect people (and even though I could argue that he went from only wanting to protect those close to him to wanting to protect everyone he can, that's not the point I'm making with this post).
I think a lot of people who only give Bleach a passing glance fail to see Ichigo's true character growth. It's not about what his goals are or who he's trying to protect, but rather, it's about how he achieves it.
Ichigo is very self-sacrificing in the first third of Bleach. He believes that if the mission is successful, then it doesn't matter how broken or close to death he gets. The mission, saving Rukia (and hurting/killing as few people in the process), is all that matters.
Then, when a part of himself (his inner hollow) emerges, and says "hey yeah no, I'm not letting you get yourself killed and I'm also not letting you hold back against your enemy", Ichigo immediately rejects it.
It's not until he defeats his inner Hollow that we see Ichigo really dive into a fight with the intent to kill. The problem is, once his Hollow is defeated, he thinks that's it. He's freed himself of that part of him and he can go back to being self-sacrificing.
We see this throughout the Hueco Mundo arc. It's why saving Orihime parallels saving Rukia. Ichigo naively thinks he can suppress a part of himself. He bottles it up until it explodes, coming back to haunt him in his fight with Ulquiorra, etc. He learns that side of himself isn't so easily tucked away, and if he recklessly endangers himself, he could end up endangering his friends too. At his own hand, no less.
Then Ichigo discovers he can commit the ultimate sacrifice. Final Getsuga Tenshou. He can throw away these powers and the parts of himself that he doesn't like, and he can get rid of Aizen all in one go. He's lucky that it worked, but only because Kisuke was there.
Then, once Ichigo is powerless, he learns that's not what he really wants. Life doesn't "go back to normal". The can is open, and there's danger out there beyond just Aizen. And Ichigo can't do anything to stop it unless he gets his powers back.
So he does. Then he cuts down the threat to his friends and family. And he doesn't hesitate this time. Yes, he still has compassion for his enemies (he even goes to the Soul Society to ask for Ginjo's body so he can give him a proper burial), but he's learned not to hold back and he's learned that new threats will appear and he'd rather have the power to face them head on.
So then comes TYBW, and Ichigo is facing battles head-on without hesitation. He goes straight to the "bad guys" with the intention of cutting them down. He learns the truth about who his Inner Hollow is, and he accepts it. He's even willing to accept whatever consequences may come from training in the Royal Palace and becoming stronger. He accepts his power and potential fully, and learns that he has what it takes to protect his loved ones with his strength, and not with a sacrifice.
Ultimately, he heals the part of himself that thinks his life is worth less than other people's. He heals the part of himself that blames himself for not protecting his mother (when he was 9!! Like come on Isshin, put the kid in therapy!! Anyway...) He grows into someone who knows his self worth. And I think, for me at least, that makes him one of my favourite protagonists of all time. Because can't most of us relate to feeling worthless at times? And don't we also wanna overcome that?
Thanks for reading my ramble lmao, I'm sure this could have been more elegantly written but I'm very sleepy and just wanted to get my thoughts out there.
