Earlier quoted context omitted.
Again, think on the margin. If there’s suddenly a lot of new luxury apartments then those looking for something cheaper have less competition from the deep pocketed. If they build so many luxury apartments that prices for them break that’s also a victory condition.
It's not so simple. The newer buildings were constructed at a much higher cost than the old ones and they are priced accordingly (and with less flexibility to go down in price). In spite of the price tag and the 'luxury' appellation, they really are not that nice (they tend to be small and the gym/pool that comes with the apartment is closed during Covid. Consequently there is a subtle structural shortage on apartmen…
That said, housing can be profitably built cheaper, but why would any sane developer make a low price house when there is more profit in luxury housing. SF has refused to allow enough construction to meet demand, and this has resulted in only luxury being built.
Cities with less growth than SF are building more than SF, and as a result all housing is cheaper.