The people buying luxury condos are usually single professionals who previously lived with their parents. Them moving out of their parents homes don't add more housing supply to help the homeless.

First, I'd love to see the data to support that. It's hard to imagine a single professional doesn't rent first and goes straight to buying a condo, especially in the North America where people generally move out at 18.

Second, if they're buying a condo versus paying rent, that's still good because it leaves less price elastic renters in the market. You can to get those who are willing to pay much more into something higher end versus them taking the bottom and increasing its price (which is what's happened in SF).