The reason that there was no record nor trace of the ancestral civilization outside of the Lost Ruins was one that had boggled geologists and archaelogists.
But when Rui had connected the alien virus theory with the theories he had come up with the Divine Doctor with the information theories that he was familiar with, he began gaining a better understood of what had happened.
The alien entity must have entered Gaia, set a manifold, and then must have wiped out all information of the past through some extraordinarily unfathomable esoteric means. Given that information couldn't be destroyed, he could only assume that it had been absorbed by the alien entity almost entirely, leaving only tiny pieces intact.
The Lost Cities.
The Lost Cities weren't particularly special places, just places that must have survived the information seizure by random chance. They were the few sole remaining relics of the past.
Of a civilization before esoterics and before Paths.
