Now, hear me out. Even though Voldemort is main villain of the Harry Potter series, he isn't even as bad as the Ministry of Magic. Here's why.
The Ministry of Magic is basically a glorified totalitarian state. Which sounds crazy at first but when you dive deeper, you actually realize how horrible of a government the Ministry is.
They have the ability to send people to Azkaban without trial. In fact, as seen in Book 4, even getting a trial is a luxury only reserved for those related to the Department of Magical Law Enforcement.
They can literally order dementors to suck your soul out. Once again, you don't even have to go through trial to go through this. Fudge ordered the dementors to destroy Barty Crouch Jr's soul without even giving him a proper hearing. Even worse, Fudge faced no repercussions for this and was allowed to serve as Minister for Magic for another year.
Obliviators. Now, the Obliviators are obviously meant for Muggles. But who's to say they aren't used for political control? If you can destroy someone's soul without giving them a trial, you can definitely wipe their memories. Say you catch a Ministry politician committing a crime? Tough luck buddy, cause you're about to say goodbye to your memories.
Azkaban. Do I really need to say more about that prison? The fact that the Ministry is allowed to keep its prisoners in such inhumane conditions is terrible.
Tracking. The Ministry of Magic can track underage wizards who use magic. And in the books we literally see this used as a political tool by Fudge who was trying to get Harry falsely expelled. Are there any other cases of the Ministry abusing this power?
Now the Death Eaters were definitely in the wrong, but honestly the Ministry of Magic makes them seem tame. In fact, the Ministry seemed to literally thrive when it was under Death Eater control by Book 7. Judging from how it behaved during the last book, it was literally waiting for an excuse to go on a power trip and the Death Eaters gave them that excuse.
The Wizarding Wars were nothing more than a power struggle between to extremely corrupt forces and even then, the Ministry was perfectly fine with working under its enemy's control.