With Google Drive's new block feature, Google is hoping to give users the ability to deal with or cut off potential harassment before it gets to be too bad. Once blocked, a user won't be able to share any of their Drive items with you, and nobody else will be able to share that user's items with you either. Blocked users also will lose access to all of your Drive items, even if they previously had access.
“Drive’s sharing capabilities fuel productivity and collaboration, but bad actors can abuse tools that are meant to facilitate helpful sharing,” Google said in a Workspace Update post, “That’s why we are creating a way to block other users. This can be a useful control if, for example, another user has a history of sending spam or abusive content.”