IMHO...
I have estranged myself from my family for a variety of reasons. I haven't/hadn't spoken to my mother or father since early ~2014 after a major confrontation. My father died in the fall of 2014 from a final fight with cancer. I wasn't there, before, during, or after. My mother is still alive, I haven't spoken to her and doubt I ever will again, unless she initiates the communication with an apology. My youngest brother was the main reason for everything that took place. He died in 2015 from throat cancer. I didn't see him, wasn't there for him, before, during, or after. My middle brother caused his own set of issues and incidents and I broke off communications with him back in 2010. I haven't seen or spoken to him since and don't expect I ever will. My oldest sister drove me away with her actions more than 20 years ago. I will never see or speak to her again, and for all intents and purposes, she doesn't even exist to me. My middle sister and I still communicate, generally once or twice a year at holidays. I have visited with her within the past year, but don't see her often.
The point I'm making here is that you feel the way you do justifiably. You do NOT owe your siblings or your parents anything on your brother's behalf. Their relationship with him was theirs... NOT yours. You have/had no relationship with him for many, many years. IMHO, you should treat it as if you never even knew him. Put the pain from the past back in the past and move ahead.