It's alive!
Imagine if an event in the future tells us the Chasm really was alive like it's the insides of an Archon and the upside down city was Zhongli using it as one of his "spears."
I think it's been made pretty clear that Liyue itself is just one of the more modern regions in Teyvat. Khaenri'ah existed at the same time but could have even predated it and even it isn't as old as places like Enkanomiya. And since Dainsleif didn't recognize the upside down city it could be that it's older than Khaenri'ah too. This could have left it abandoned by the time of the Archon War so Zhongli might have just used it on one of his rivals.
Tips and Tricks from a Super Casual Genshin f2p
