There are no evil people, media (books, TV, movies) have plainly evil people so the story is easily digestible and appealing to the masses. But it is completely incorrect framing of how the world actually is.
In reality "evil" people almost always want to genuinely make the world a better place, and they are fighting "ignorant" people who are dragging society down by not conforming to their golden vision. And then "evil" becomes largely a function of who you ask. It's the opposition that labels them evil, not society on the whole.
There are very few leaders ever who are straight up storybook style evil. Almost all of them were/are deranged people who convinced enough people of their ostensibly good vision to begin executing it.
No one came to power because they wanted to turn society into burning rumble while they ate babies during daily random execution time. It's all nuance and complication.