The Death Star was a feat of technological and architectural innovation, the likes of which may never be seen again. It was a fully-functioning, smooth-running MOON-SIZED battlestation. Ya know how big MOONS are? PRETTY F*CKING BIG. Especially since it wasn't just people living on the surface-area - they were living on the INSIDE of this robo-moon. You know how many floors there probably were on the Death Star? How many people it held? We're talking (conservatively) an unimaginable f*ckton of people. Like, 10 million sounds low. New York City doesn't have 10 million people, and that's a hell of a lot smaller than a moon. 100 million? 10 billion? All of these are pretty reasonable numbers, given the circumstances.
That being said, the architects behind it deserve A LOT of respect. Maybe you've read our transcript of Dak Exhaustport's defense of his design. But if you're not into reading (and if you're on the internet, I know you're not!), then you can finally hear his words straight from his pixelated mouth: