Seth could be one of the next top guys and replace Roman as far as main event status and dominance is concerned. In terms of sales, I think it could happen, he just needs to continue down the path he’s on: good feuds, good wrestling, more interesting Shit than just saying “I’m Seth freaking Rollins, the King Slayer.” Which that means nothing today considering how many people have beaten triple h at mania, and also because triple h is still perfectly fine and competing at mania like nothing happened.
Seth is the better wrestler, has a better build, and can talk better, so I feel he would be a better pick. Then again, Braun Strowman is also a better pick, and hell potentially lashley at this point. I know this thread is about Seth, but the point is lots of stars seem to be better for the main event role push than Roman.