While it may seem like there is a disproportional number of good guys versus bad guys, I'd say that may not be the case. When done well, evil and antagonistic characters can maintain a cover for a long time to gain power to be able to reveal themselves.
I've played basically exclusively antagonistic characters (with a few exceptions like Odette and Narcissa) and there is nothing that you need power or extra tool wise to be a good villain. It's in the character creation, in their story and their desires and goals. If you're worried about being "roflstomped" I get that, but that hasn't been happening much to my knowledge, it does still happen but when it does the antagonistic character has made themselves noticed by their actions. It can be discouraging greatly so when your hard work gets cut short, but that's the big thing to remember when playing a villain.
You are the villain in someone elses story.
Your goal as an antagonistic character is to create trouble, to generate roleplay that encourage people to go after you. You are the main character of your own story, yes, but as a shared narrative, you are the evil bad guy that someone wants to put a stop to, that someone wants to kill, or eliminate. When you're a villain your fate is less in your hands and more in the hands of those who would go after you. It's not easy and it does suck when cut short, but that is the risk of playing an antagonist.
The earliest villain I played was Cozette, followed by Tess, Milicent, Lily the reluctant werewolf, Sasha Dominika gaspar, Erzsebet Varga, and more. Every single one of them ended prematurely. Only one of them ended with roleplay, and yes I was upset, you're allowed to be upset, but I don't think we need a special permission style application to play a evil villainous character. Most of the villains I made that became well done were the direct result of the rp that happened to them as they levelled up in power.
In the past there have been groups of players who have organized antagonistic groups for play. I remember partaking in a group of Falkovnians before the first war happened, and that group was purely players. There is nothing stopping you from getting people together OOCly to create a antagonist group and plan your classes so you can dungeon together and level up. We did that when tess was in the cult of nerull, we would dungeon together frequently to get stronger.
There is no need for an application process to be an antagonist. Best advice I can give is to create a character that does not believe they are evil, give them a reason for what they do. Why does the necromancer a necromancer? What happened to make them go that route? Why is the rebel joining the rebels, what happened in their past? Is the Falkovnian willing or forced to do what they do? A port gang, are they poor trying to make their way, or are they trying to get revenge on the upper rich class? Giving them these reasons tends to make the character more easy to get friends and people who will side with them. If you're a necromancer because you just want to bring dead things back for fun, no one is really going to want to help you, but if you are a necromancer who is trying to understand how death works so you can stop people from aging and dying, you may have better luck.
Playing an antagonist that will last for more than a few levels is hard work, it's not just about being mechanically powerful, it's about the driving reason behind them. I love playing villains and if anyone would like advice, feel free to contact me, I'm also usually open to most villainous things. You don't need mechanical goodies or yellow text to be able to play an antagonistic character that will last. Shortest lived villain for me was a three months I think? Or 30 days if you count my ampc Lily. Longest, was 6 years and that was Erzsebet Varga.
If you let the story drive them, you'll find more fulfilling roleplay and an even more amazing story.