#3 Bobby Roode (SmackDown)
Bobby Roode was a hit when he was in NXT. He ended up becoming the NXT Champion as well. He was brought to SmackDown with much hype, and he rode the wave to become the US Champion.
He subsequently lost the title to Randy Orton later on but he was able to establish himself very well among the other stars. But then he got drafted to Monday Night Raw.
Charlotte Flair to return and wrestle a CURRENT CHAMPION?
When that happened it all started to go downhill for him. He was caught in the crowd and it seemed like the WWE management forgot about him completely.
When you have stars like Roman Reigns, Dean Ambrose, Seth Rollins, Braun Strowman, and Drew McIntyre, that's a pretty long list of superstars who already occupy the spotlight.
And because of this Bobby has hardly had any storylines for him and has been just added to a tag team with Chad Gable. The tag team is sometimes on air and sometimes not.
Moving back to the more familiar lands of SmackDown could help Bobby be himself and really get more time on-air and maybe better feuds which would propel him up the card.