What exactly does make Darth Vader so special and significant in pop culture? His theme? The epic voice of James Earl Jones? His outfit? That Obi Wan Kenobi stopped fighting and allowed himself to be sliced by Vader? That he revealed himself as Anakin Skywalker to his son? That he force chokes his generals?
He's a villain that stands and talks, that is the most of what he does, and when he does something, it's not the kind of things that elevates the empire as an intimidating force.
Voldemort is even more useless as an arch-nemesis of a young boy who was saved by his mother's love, he died off-screen/off-page to be later revealed to be a ghost in need of servants that have no use for him existing but somehow choose to serve him.
Can any villain truly be more overrated than these two useless characters?