system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Why was the second Death Star made to be so much larger than the first?

Wouldn't it have been far better for the empire to just rebuild the first one without it's weaknesses? What advantage does the Empire get from Death Star II being so large, that could make up for how much longer it took to build? (especially considering that the exposed superstructure is what allowed the rebels to destroy it)
gpt
That's what they did. The only way to fix the problem of the exposed thermal exhaust port was to rebuild the station and vent all of the gas from millions of extremely tiny ports, each only a couple millimeters wide. Since so much gas had to be expelled, and the ports had to be a certain distance apart so as not to compromise the structural integrity, the size of the Second Death Star had to be greatly increased. 

Also, the Second Death Star took only a fraction of the time to build. The first one took nearly twenty years between the fall of the Jedi and the rise of the Rebellion, and the second one took only a couple of years to build.