Test was a guy who at one point was pretty over and could’ve become a top superstar. He was put in the biggest angle at the time with Stephanie and hhh. He was a big guy physically too. I’m guessing his personal issues and mic skills halted that push
D-Lo Brown was really starting to get over as the European champion and I remember he started getting some large pops from the crowd. Idk why his push stopped but this was well before the droz incident
Billy Gunn was another guy who got a pretty good push. He got to work a program with the rock but he couldn’t deliver the goods according to Bruce Prichard he had an asthma issue and maybe singles wrestling just wasn’t for him. Also his mic skills were subpar.
Who else comes to mind?