I remember a lot of people getting frustrated and hating on the character for a plethora of reasons. One such was that he was a wimp shying away when the going got rough. He often crumbled beneath the weight of things, especially when the stakes were high. He was far from the stoic badass or the optimistic type. He was fearful of a lot of things, a growing boy that hardly knew what he wanted from life.
All these things are reasonable. What could you expect when you put a boy in the position of having the save the world? This to me is a great and desirable trait in making a good protagonist. Realism. Most authors want their protagonist to be somewhat of a badass, especially regarding webnovels. Likewise, these same authors get called out for this with a review commenting that what they're writing is fundamentally a self-insert.
It's more than fine to have a stoic badass for your protagonist, but most keep the character that way throughout the entire plot from beginning to end. The most impactful and memorable stoic characters that come to mind are the ones that have their stoicism broken in, either through fear or love. They gain attachments that make them vulnerable, or so much is put on their shoulder that the armor that is stoicism breaks, perhaps permanently or temporarily.
To me, a good protagonist is one that struggles. He wins some and loses some, and the future isn't predictable. Neither the protagonist nor the reader knows if the ending is a happy one. To me, a great protagonist is one that you both love and hate. A character that can give up when you want him to keep on. A character that will hesitate and make mistakes that makes the reader sigh in frustration. Fundamentally, a realistic character.
I mean sure, you can have a badass that wins nearly every battle, and that can certainly work in your favor if you do it well. However, does the protagonist always believe he will win? Does he have no fears at all, no doubts or imperfections? Is there any cost to winning?
A protagonist you hate for all the right reasons is a great character. Ikari Shinji is just one such example.
She's got a heap of mental health concerns (voice in her head, depressed, anxious, paranoid, barely able to care for herself); and keeps wondering if she should walk away from the new life that's being presented to her during the first book (ie, "I can't remember to take out the trash, people shouldn't rely on me for anything" kind of thing), but with some accommodations and support, she decides to give it a go.
I like characters that mess up, but learn; characters that can take joy in little, relatable victories.
The character doesn't have to be overly flawed and to never be this perfect being winning perfect badass. A power fantasy character is only fun for a few reads, but then I get bored. I like a character who feels real and not an ideal.
Character who doesn't always have their ducks in a row for every situation, doesn't always have answers, will try their best, and stumble. That doesn't mean I want a character who is constantly failing. Like the winning perfect badass, the butt monkey who never has anything good happen to them is just as annoying.
I think it boils down to what produces the best conflict in a story. An active protagonist who goes out and does things and picks fights is good in a story where the status quo is in need of upsetting, but not necessarily in one where it needs protecting. A protagonist who undergoes dramatic character development is good in a coming of age story, but maybe isn't helpful or entertaining in a mystery story where you aren't looking for character focus like that. Even something like a flat 2d character which is typically considered bad might be good if framed against a very cynical world where their simplicity might shine through. You could even have a protagonist who hits every positive note you want to see in a character, but they still might fail to be entertaining because the supporting cast does a better job at filling that role!
Protagonists (and characters in general) don't exist in a vacuum, and one story's courageous warrior hero who fights for their friends might be another story's reckless blindly loyal thug. In my opinion, setting and how a protagonist fits in with the rest of the cast really determines how 'good' they are for any given story.
If your protagonist has less confidence at the beginning of the story, they should gain more confidence at the end, not the same amount else nothing had happened to gain the interest of the reader, no development has been made.