does anyone else just dislike their sibling?

I feel like this isn't such a crazy thing when you read it but i have never met someone who is like me in this way. I'm 20f and live abroad from where i grew up. i have one younger brother (18m), 2 younger stepsisters (tween and teen) and a very very young half sister who i never have and probably never will meet.

I guess my brother and I got along when we were really little, but for as long as i can remember, i didn't like him. I remember just wanting him to go away, and he would usually have my mom intervene to force me to pretend that i like him/include me. i got in trouble a lot, (and even do now, but now she can't 'punish' me/being in trouble with her holds no weight to me now) for not wanting to play with him, hang out with him, do things for him, etc. one particularly heinous example was my mom demanding that i make him part of my high school friend group when he started at my high school, which i refused and was punished in some way.

I can also always remember being told to cook and clean, while the same thing was never expected of him. My mom denied it being because of our gender, and said it was because i was better at cooking and cleaning. I argued back that this was because she always made me do those things, and she just ignored it. i think she has major cognitive dissonance.

now as he's older, i don't like the person he is at all. He doesn't work (I had to get a job as soon as it was legally allowed), he didn't graduate high school, and he lives at home despite my mom making a big deal out of saying she'd kick her kids out at 18, which was waivered for about 6 months for me since I had concrete plans to move abroad. He has no concrete plans to move out but she's making excuses.

He also was in a relationship with a much younger girl and mistreated her in many ways, and people from my hometown called me asking if i associated with my brother, since many viewed him as a predator, so unbeknownst to my mother and brother, i have pretty much publicly disowned him.

I don't think it's about me not coping well with the sibling dynamic either, because i do love and admire my 2 stepsisters, who of course have their issues but are really nice kids who i am proud of and like to hang out with when i can/could.

I feel like i don't like him at all, but my mom keeps telling me it's abnormal, and i don't know anyone else with this mindset about their siblings. I would be pretty happy to never interact with or think about him again, and it's annoying how my relatives who i'm close with keep expecting me to be close with him or feel sorry for his bullshit, and i stopped pretending a long time ago. does anyone else relate? can anyone explain this feeling and tell me if it really is abnormal? my boyfriend says that if any of his siblings were like my brother, he'd feel the same way, but he even seems to have affection for his siblings when they're behaving pretty badly, so i don't know. it just seems weird to me.