#9 Chad Gable
Unlike the aforementioned Colóns, who are just not being used period, Chad Gable is popping up on TV every few weeks but is deeply lost in the shuffle. I think a big part of the problem for Chad is he has always been portrayed as a tag team wrestler. From American Alpha with Jason Jordan to Shelton Benjamin to his most recent team with Bobby Roode.
It is a very popular opinion that Gable's team with Roode was just out of place and didn't really do either man many favors, despite winning the WWE Tag Team Championships on RAW. Despite that, it is still probably a little better than his current position of just showing up on SmackDown every other week to put someone else over.
I think WWE needs to strike with Gable soon and stick him in the Intercontinental Championship ranks and work his way to being a credible Champion. If not, they could still play it safe by having him reunite with Shelton Benjamin, just at least to give them both something to do. And, they were actually a decent team, so Tag Team titles shouldn't be out of the question. Despite all of these possible options, WWE just refuses to do anything with him, but I think he could be a pretty good candidate for All Elite Wrestling.