AI replaces a single tower with millions of 5-over-1s[1]. The aggregate height, and speed of construction mind-boggling, but when each building is considered individually, not very impressive.

1. Perhaps with a handful of skyscrapers sprinkled in.

so the post-AI landscape is software as a shanty town? That's not a bad analogy. We won't like the looks of it and it will barely function but like real life shanty towns it will function nonetheless.