That's an extremely high bar. But to the extent that critics and awards are the metric we have, he is an objectively good writer.
I don't know that you can establish objectively if someone is a good writer. He's an acclaimed, award-winning writer, sure.
Oh course it's a high bar! Why should anyone care about this work outside of the time of their release? It's modern culture but it ain't gonna be passed down anytime soon.