I think Ponyboy's view on his relationships with the other Curtis gang members is really interesting because I believe two things:
1.Ponyboy doesn't truly see how much the others care for him because of his insecurities.
2.Members of the gang may just not like Ponyboy...and what he says about them in the book may not be as far from the truth as the fandom likes to believe it is.
I am a youngest child who has been teased my whole life and I can definitely say that I have been convinced that people hate my ass when they most likely don't. Ponyboy isn't trying to be unreliable in his narration it's just what he believes based on his experiences. Steve is an dick to him, and whether or not you believe that he secretly has a soft spot for Pony, it makes sense that Pony would hate Steve and think that the feeling was mutual. I love Steve & Pony fics that explore their relationship but like...dude I have been in Pony's position!! It sucks!!! I get why he thinks Steve hates him because, in a way, Steve probably does!!
And with Darry, I can 100% see why Pony thinks Darry hates him. I love Darry with my whole chest but he is kind of an ass in the book to Pony, and there is a definite difference between how he interacts with Pony vs Soda. Even though we, as the reader, can see why, but Pony cannot cause he's 14 and insecure and still getting used to the shift in dynamic between him and his brothers. Maybe I'm just biased cause of my life but idk man.
I had examples for all the other characters but none of them made sense so...I hope you guys understand what I'm saying.
Also being the youngest in a group (esp when the group consists of your siblings and siblings' friends) is awful. 0/10 do NOT recommend. You think everyone sees you as a bother or whatever or that you're just tanging along with the big kids because your older siblings are forced to. You are never fully convinced that they aren't just waiting for the right chance to kick you to the curb.
All I'm saying is that, if I were in Pony's position, I would also be convinced everyone (minus Soda and Johnny) hated me and didn't want me around.