One of the other nice features of Swiss rental law is "imputed rent", which is rent the government assumes you have collected even if the property is empty, and upon which you are taxed. Discourages keeping properties empty.
That's not equivalent, I hope you're being sarcastic.
People who can afford not to rent out an expensive property are almost by definition multi-millionaires.
Those people (and those properties) do not make up all, or even most, of the picture.