That's extremist, terrorist propaganda!!

There is only one Vader boi & he can't personally chop that many not just the men, but the women and children too.
And the mad lad is just sent on hotspots as a deterrent basically.

And most of the time he fights groups that were established & hoarded their corrupted wealth under the Republic-sanctioned orders.

The Republic artificially maintained wealth classes, kept some planets poor just to solidify it's government's reign & power.
With resources to eradicate it all.

The Emperor could easily close those tax loopholes if he wanted to, but that might hurt his rich friends.

The Death Star was a huge waste, and the military knew it. You could tell by how Grand Admiral Thrawn dodged the question when a reporter asked him about it, and then had the reporter imprisoned. He knew full well those credits could have paid for at least 2 full Imperial Battle Fleets.