If you have nigh-unlimited energy -- and crazy people do too -- then planets become remarkably big targets. And space habitats become a practical alternative. That could be an interesting setting, and remarkably non-dystopian.
What do you mean by "nigh-unlimited?" Even if you have a store of energy that doesn't run out, thermodynamics will bite you if you try to use too much of it at once.
planets become remarkably big targets.
Even 1970's tech has access to huge amounts of energy for targeting planets from space, if all you want to do is to destroy stuff.
And space habitats become a practical alternative. That could be an interesting setting, and remarkably non-dystopian
"Burning Man in the Oort Cloud" has been done. There's still a lot of potential there, though.
