So is Iron Man's rogues gallery on filled with people in powered suits? I mean.... Certainly there's someone else we can see.
a lot of them have either powered armour suits (Crimson Dynamo, Titanium Man, Firepower, Sunturion, Ghost, Iron Monger) or used technology gimmicks (Whiplash, Melter, Stilt-Man, Blizzard), only a few, like Madam Masque didn't.
if your hero's a guy in a power suit, you need people to be a credible threat to him, so power suits proliferate.