Villains! They’re the salt of a story, aren’t they? Good folks are perfect in real life, but on printed paper, they need villains throwing obstacles their way.
However, a good villain should have depth and nuance. Creating a character that’s 100% evil might work if you’re working on comics—The Joker, anybody?—and not so much when it comes to a manuscript.
I’m not saying, go and humanize your villain, no. They might be poor boos who got the short end of the stick, or they might be your average prick. They might be redeemable and go through a growth arc, or they might be a lost cause. The important thing is to write them in a realistic way. A good example of what I mean is MCU’s James ‘Bucky’ Barnes: his arc is fantastic.
Think about a real-life someone you don’t like. Flaws aside, they probably have some good traits, too. Maybe they make the entire office miserable, but they rescue kittens down the alley? They care for that one person? They never forget to water their plants?
Nuance is the key. Write your villain, but don’t go overboard.