This UserScript aims to bring a better experience to the new Goodreads Bookpage by resizing and repositioning the elements on the page. Based on tripu's Wider Goodreads.
I don't use Brave but I tested it and it works for me. Are you using some other extensions or scripts that might be interfering? Or maybe your browser isn't up to date?
unable to get it to work with Tampermonkey on Brave