The situation in Greece is very different, as everything is a highrise (sadly, because we tore down a lot of beautiful centuries-old antique villas to do that). The situation used to be much better, but the start of the problem coincides suspiciously with the rise of AirBnB, and you'd expect housing prices to drop in a recession, not rise.
That's why I think it's fair to blame AirBnB for that. We'll see what happens in Tokyo, Madrid and other cities where they're severely restricting usage.