Welcome to the SR family!
I'm glad you found us, but sorry for the reason that brought you here. Please make yourself at home by reading and posting as much as needed.
Is there anything you can do to change your parents? I don't think we have the power to change another adult. I know I only have the power to change myself.
I respect your decision to not visit your parents home while your brother is there. I think that is a healthy decision to limit your contact with toxic people, even if they are your relatives.
I see that your parents are hoping that
"this time will be different" and trying to love your brother into acceptable, responsible behavior. I'm sure that is very frustrating to witness.
I hope you will consider attending Alanon meetings in your community for some face-to-face support. You will find like minded people, like here, that support you as you try to make healthy decisions for yourself while dealing with a loved ones addiction.
Welcome!