What do you think of me cutting my brother out of my life?
Do you have a problem with your brother?
There is problem, he won't leave his adolescence behind. He always wears childish T-shirts and I want to be the one who chooses his clothes for him.
It is normal to want to want your brother to be cooler but you cannot force them to change. It is also wrong to cut them out of your life because they won't change for you. You might miss him.
It's for his own good. He's such a loser.
You won't help him at all by cutting him out of your life, and it would be hurtful to him for you to not want to associate with him anymore because you think that he is less than you. Overall, a brother should be helpful and kind to his siblings and you have the opportunity right now to do this for your brother and help him out.