#1 Daniel Bryan's heel turn
Daniel Bryan shocked the entire WWE Universe when he won the WWE Championship from AJ Styles with the help of a low blow. Bryan's heel turn was not at all expected. He is one of the best faces in the history of WWE. His heel turn was unnecessary, and was poorly booked by the WWE.
Bryan won the WWE title and went on to face Brock Lesnar at the Survivor Series PPV. Everyone knew beforehand that he stood no chance against Lesnar. Therefore the question still remains unanswered - why did WWE make Daniel Bryan turn heel and win the WWE Championship?
This shows lack of creativity on the part of the creative team. The WWE management should never have allowed these mistakes to happen. They should be careful in the future, and think of long term consequences, and not short term profits.