I was suggested the video by youtube earlier today. It says that half the falts are empty, even the most expensive ones. Someone pays 250 millions for a flat and never uses it, even once. What a waste !
It was also suggested that maybe it wasn't the best investment, because at first, with one such tower, it was "unique", but now, like you say there are several hundreds of them.
There's a glut of cheap money on the market. Everyone's looking at Bitcoin as tulip mania but nobody's looking at the elephant in the skyscraper.