I agree fully with this for the reasons LSN80 just stated. Edge routinely troubled the top stars while remaining relevant and at the top of the card for a decade. Roddy is just as good a heel, but was never as much of a threat to the top talents.
The only way this doesn't hold up is if Roddy's era was harder to be relevant in. That's pretty debatable imo within kayfabe - I do think Hogan>Cena marginally, but let's have a look at the rosters.
First thing that jumps out for me is that both men were top 5 in WWF/E for their prime decade.
1980s top five - Hulk Hogan, Andre the Giant, Roddy Piper, Randy Savage, Ted DiBiase.
2000s top five - John Cena, Triple H, Edge, Batista, Randy Orton
I think those are fairly undeniable. What's interesting is looking at the next five down to get some context of how tough it was to hold that top five ranking.
2000s - Undertaker, Shawn Michaels, Kurt Angle, Brock Lesnar, Chris Jericho
1980s - Bob Backlund, John Studd? The Ultimate Warrior? Paul Orndorff? Iron Sheik?
1980s is really hard to define as no one remained relevant for long in the main event. Backlund was done by 1984, Warrior wasn't main event yet. Sheik was transitional, Studd never really had a title feud.
Anyway, the point is Edge won a LOT in a far harder roster to do so in. You can point out Piper going clean over Hogan in WCW, but it wasn't his peak. His peak was being a dick heel and main eventing the first Wrestlemania a #1 heel in the world. He was brushed aside and never got the title win at the time though, although it was very hard for a heel to win granted. Regardless, Edge has done far, far more and should be good for your vote here.