My problem with Petra is... what do you do with all the Production?
It’s the same problem with giant Three City Aqueduct Dam Industrial Zone constructions and various other Wonders high Production Cities.
All very fun for the Meme value, but by the time I’ve built them there’s very little useful they can actually do (or, really, build). I usually end up just pumping out a few extra units, then flip these Cities to running projects, which is not really much of a fun pay-off.