Why is it that often in stories describing dystopian futures the takeover of nature is a indicator of decline?

It's an interesting question when looked a little differently; why is it that often in pictures showcasing human progress the absence of nature is an indicator of success? I say this in reference to any of our modern skylines.

Your question may have been rhetorical, but I think the reason is that humans think they're better than Nature. After all, we take every single one of her free gifts and repackage them for a price. Even air! Carbon tax. For some reason, despite working solutions proposed by nature, man's ceaseless desire means that everything for free isn't enough.

Why is it that often in stories describing dystopian futures the takeover of nature is a indicator of decline?

Because it shows that Humans have lost, and aren't really as smart as they think they are.