I will leave this link here.
https://www.sports-reference.com/cbb/coaches/roy-williams-1.html

But to answer your question on how they are this bad is they relied heavily on on player, Anthony, and now that he is out they are not a full team. This is Roy's fault for not recruiting a complete team, but he also has never been known as a one and done guy, and with him testing the waters of this route it will lead to some troubles. He will leave when he is tired coaching.