#2. Stardust - the gimmick that killed Cody Rhodes' WWE career

This is perhaps the most WWE positive entry on this list because we now know that it resulted in something much bigger than anyone would have expected. When Cody Rhodes turned into Stardust, it was clear that so much more could have been done with him.
While he was involved in a few entertaining feuds and matches, the gimmick had run its course quickly and everybody knew that Cody Rhodes had so much more potential in WWE. However, things never seemed to work out for him and he even revealed that he was supposed to win the Money in the Bank briefcase before, only to be told by WWE that "plans had changed".
He requested his WWE release and was quickly granted it - citing all his creative frustrations. He said that he wanted to return to being Cody Rhodes for a long time. His departure from WWE would see him become one of the hottest independent wrestling stars, resulting in runs with NJPW, ROH, and eventually ALL IN and the formation of All Elite Wrestling. It's safe to say that Cody Rhodes realized his potential only after his WWE career got derailed.