Look, the Empire was two things that were frankly unforgivable and justified their toppling:
1) Excessively racist
2) Excessively British
Tales of racism by the Empire are notoriously overstated by their political enemies; you'll find almost no examples of it in the movies.
You know who was really racist? The planet of Naboo. Another false democracy that "elects" a series of 16 year of girls to be figurehead rulers, conveniently swapping out one child queen for the next whenever she gets too old. Meanwhile the real puppet masters, like Sio Bibble, control the government for generations as perpetual "royal advisors". This ruling royal class of Naboonians decided that only the humans should live on the surface of the planet, controlling the planet's trade and all involvement with the Republic. Meanwhile, the entire race of Gungans was banished to the water and given no representation in the Senate. Of course, all of this was completely sanctioned by the Republic.
Please note that I'm not saying the Empire is "good". I'm just saying that of the three galactic governments we've seen in the Star Wars galaxy (Old Republic, Empire, First Order), it turns out the be the least evil. It's an unfortunate intersection of "show vs tell" storytelling and writers who don't consider the full implications of the minor details. We're told the Empire is evil by it's enemies, but shown relatively little of it. Meanwhile, over time we have been shown more and more examples of what the Jedi and the Old Republic do, and their actions are basically terrible when you start to analyze what actually going on.