I think some people fail to understand that Subaru's not an all-forgiving saint that only selflessly wants to save everyone and regarding him as such is just terribly dehumanizing him.
He's indeed extremely kind, but a big part of his behavior is an ugly mess of trauma responses, his desire to save everyone at its core is chance that they're not all bad and they might become another one added to the list of people he has to save; His love for them contains a controlling possessiveness which he's aware of and unfortunately develops over time as more and more deaths pile up (and it's really born out of so many unfair terrible situations he never had any control over).
He possesses an insane mental toughness but he's emotionally extremely fragile, so he's willingly indulging into extremely toxic and self-destructive mindsets and relationships just because they enable him into shaping reality into something emotionally bearable and run away from the natural occurrence of loss or the concept of being rejected: As long as he's kept around, he'll die for others, he'll forgive any wrong that's been done to him, he'll take the blame for anything.
His constant lack of autonomy in experienced traumatic events shaped his psyche in a way that demands control over his relationships that shows through in the way he utilizes RBD (obsessive over keeping everyone safe even if it's doing things behind their backs, later content going on about how he wants to stuff everyone in a little box so that they can always be in his sight and protected for a few spoiler-free examples).
Not to confuse with "manipulative" by the way, as he is the opposite of that: He always seeks to understand and reach the others' hearts in order to reach an understanding. I won't get into spoiler territory but arc 7's Brotherhood of Pleiades SS showcases this aspect very well, Subaru explicitly doesn't seek to manipulate people but to fully understand them in order to connect with them, love them, and in the end never let them go.
He confuses vulnerability with a loss of control which leads to pain and death, so he avoids it like the plague, but he knows it's not something he can run away from forever, hence why he desperately seeks enablers that praise his self-destructive behaviors and don't let him rest even in the presence of his human weaknesses he detests, because accepting them would mean being left unable to run away from the unavoidable, natural and yet downright terrifying sense of loss and abandonment which is, in turn, caused by his distorted sense of self and pervasive sense of emptiness, a perceived lack of identity.
He defines himself solely by what role he fills for others because his own self is empty, and if he's perceived as an all-forgiving selfless hero that brings everyone salvation, then that's what he should be, even if it's inherently dehumanizing and self-destructive. Subaru fails to distinguish where "Natsuki Subaru" ends and where the people he loves begin, because he intrinsically constructs his identity around other people. As follows, losing these people means losing himself.
disclaimer: this is a very short analysis I wrote on twt a couple of days ago and decided to post it here asw lol
