The thing with Dave is unlike anyone on the roster now, he had a package you can sell. Look at Punk when he faced Rock, whenever they talked it was like Rock was talking to some Joe who could have been a front row fan. He can impress in a ring but nothing truly stands out about him. When Dave was elevated, he was the guy who they could truly sell as an animal. He had the physique, he had the intensity, he could work a crowd with a simple thumbs up and down, and so on. It was always easy to tell someone who is casual look at him, as he is easily remembered much like Cena. He was the true 1B they never have come close to replacing and whose shoes Orton nor Punk could never fill despite being pushed down people's throats and been given chance after chance.
Edge was a unique case you are right, but he was on the right path before his first neck injury. They were pushing him during the invasion. He had the whole Highlander appearance, Rb Zombie theme, and was wearing singles gold because they split him before they did the other attitude era teams. He just got hurt and came back into a new world with a brand extension. He took a while to get his footing back and then get to the top, but the difference between Edge and Punk or Randy or even the likes of Jericho who they bring back so much, he mattered. When Edge got there, much like Batista he drew. Edge was unique, he had a certain look to him, he could carry ratings for a show where Punks reign lost them and everyone of Ortons did. Edge was just a larger than life character with the whole Rated R Superstar thing, and he never was an afterthought on his brand because he didnt need someone else to draw for him much like how Punk/Jericho was down right ignored years ago heading into mania because people werent watching for them yet were tuning in for Rock/Cena and Taker/Trips.
I see a lot of same ceiling guys. Punk, Randy, Bryan, Sheamus, Ryback ... All the same ceiling, which is sad because their ceiling is the floor for guys like Dave, Edge, or Cena. This is also why I still won't ever be shocked if they pay for Jeff Hardy to return, he showed more potential for a payoff than Orton or Punk now