It is already - in the my opinion deeply silly book/movie series(?) Mortal Engines. I haven't read or watched them but saw a video ad and thought that it was the stupidest thing I had ever seen. Anyway it is effectively landships except they are massive steampunk mobile cities which grind up and harvest other sessile settlements and smaller mobile ones. I get the extended metaphor involved of colonalism and enrichment by exploitation of the weak and pillaging instead of their own production but even for YA Dystopian it is just too dumb logistically for me to suspend disbelief.

The books are much better than the movie, but it's not exactly hard sci-fi. They predate the big surge in apocalyptic YA and are much better than they deserve to be. They're not less plausible than "Cities in Flight" or "Marooned in Real-time" or anything with warp drives and laser pistols.

Instead of dystopian, I'm surprised they're not calling them stagnant water communities/cities.

Cities like Detroit and other areas past their prime did not devolve into madmax scenes, but instead are left with a bunch of toxic funk floating in a cesspool.

Definitely not somewhere you'd want to settle down.

Clearly you've not passed through northern New Mexico.

isn't this essentially a 21st century castle?