Viewers are curious to know why Dame Prue Leith left The Great British Bake Off. She initially served as a judge on BBC Two’s Great British Menu, which she left to join Bake Off. Here’s what happened and why Leith exited The Great British Bake Off. Why Dame Prue Leith is leaving The Great British Bake OffLeith revealed that she is leaving The Great British Bake Off as she wishes to “work less and play more.”She wrote for the Spectator Australia, explaining why she decided to step back and reflecting on her nine-year journey on the baking show. She said, “I have been dithering for years about when to stop judging The Great British Bake Off.