So I finally actually post about Steven Universe, and I decide to talk about this goober*, of all characters:
The series has devoted at least three, maybe four episodes by this point to him, all of which boil down to Lars maybe learning he shouldn't be such a jerk to people all the time, and should appreciate his friends or something. Except he has to learn the same damn lesson all over again by the next episode that focuses on him. It's a little frustrating, especially since most other characters that get that much focus make some kind of progression, their perspective evolves, something.
Maybe he resists it because all of it involves Steven meddling in some way. It had to be pretty jarring to learn that everyone (except Sadie) liked Lars better when he was acting like Steven. Because Steven had accidentally wound up in control of Lars' body. And when he found out and freaked out at Steven, everyone yelled at him. Maybe that's a difficult situation to take lessons from. Or, it's just difficult for some people to change.
For some reason, years ago, I read part of an interview online Garth Ennis did about The Boys. He mentioned people being mad that Hughie was, at the end, still making the same decisions. Ennis argued, as best I can remember, that people don't change that much. That Hughie would still be much the same guy he always was, for good or ill. It's not a universal rule, but I know for myself, attempts to move outside my normal patterns at social events don't tend to last long. I can try to be more involved, but after awhile, I drift away from the crowds to the periphery, where there's less noise, move breathing room.
I don't know if that's what's happening with Lars. We rarely see him making the effort to be kinder or more open before falling back into anger and defensiveness. But all the hints and nods to Lars having been friends with Reynaldo, or the times he's worried about how Sadie feels about him, suggest we're supposed to see it within him. He just has to chose to follow those impulses, rather than burying them under fear people will laugh at him over those personality traits. But on the show, if characters actually show a better nature, they tend to act on it when the chips are down. I'm not sure when, or in what form, Lars' nature will show through, but I believe it will at some key moment.
Which isn't much consolation to the people sick of having to see him learn the same lesson over and over again right now, but maybe it'll be something.
* Forgot to add my footnote. Someone retweeted another person who had screencapped someone in the comments for some Canadian news site. The comment was complaining that liberals were calling anyone who didn't go along with them goobers and slack-jawed yokels, and the tweeter wondered who still called people that. Answer is that I do, at least. Look, I get easily frustrated with other drivers and sometimes profanity and euphemisms for profanity don't work. And "Spud Hammlicker and his pumpkin truck" only fits in particular situations.