I've always found it funny that the reason why science fiction and fantasy villains are almost always such lackluster characters is because science fiction and fantasy writers have to stick within the realm of plausibility whereas real life villains are not hampered by such trivialities.

Your sci-fi villain has to have a tragic backstory where he's using the power of the universe killing machine to bring back his dead girlfriend or something.

In contrast, your real life villain is organizing a civil war militia to protect himself from enemies that he imagines existing somewhere even though he has no proof whatsoever, and all over the Western world people are proudly following these nut bags and even buying the merch.