True, as long as the market is competitive and people can't make money by holding appartments. So it may be necessary to use vacant home taxes like Amsterdam.

Anything that creates supply is good. Luxery appartments make people move out of other appartments. Supply increases, rents go down.

But of course, to quickly build enough appartments for everybody and bring rent down to 25% of costs of living, or even 5%, is even better. https://feddit.org/post/34635067/14682965