Give me a reason why Darth Vader isn't the coolest villain ever

Seriously, none of the villains I see in movies today come close to how epic Darth Vader is. Even TROS's Darth Vader was kick-ass.

He even has a cool background, in that he was never "fully evil" and struggled to balance good and evil. And then there's his costume.

He kind of went out like a bitch. One of ..., but not THE COOLEST villain. Rogue One was a good reminder though.

Still got into force heaven so I mean, was he really THAT bad?
his ship got knocked by han solo which basically directly resulted in them losing the death star

thats kind of a big fuckup considering he has the force and all

other than being menacing to rooms with a few people in them what exactly did he do most of the time
When I watched the OT as a child, Darth Vader never spooked me. He simply doesn't have the aura of a villain despite his costume and demeanour.

He still stands as a rather unremarkable and boring villain.
Because he killed the women. And the children too.

Also he couldn't get through a simple door on the space station he was in charge of to capture escaping prisoners. Never letting that go.
Also when I think 'cool', it's not so much in line with 'badass' as it is being threatening, powerful (within reason for the story), seemingly untouchable for a time, darkly funny, and in control. Often, for me, this comes to mind:

The prequels killed any cool he had. Deep down, he is now that whiny Anakin who dropped his allegiance and killed everyone on pretty much a whim. Before you could think of some cool backstory in your head that would make his fall seem tragic, but nope, he is just a dumb whiny asshole.
The voice

The design

The memorable lines

All you need. I think Joker is right up there too because he meets those three criteria as well. T-800 as well.