One more thing:
> something as simple as lowering rent prices
Suppose you solve that (by market means, constructing an incredible amount of homes, or by communist means, by draconian rent-control cutting all rents by 70%). A 2-bedroom apartment in SF is now $1,200 and there are 50,000 of them vacant. Would these apartments not be immediately rented by 50,000 households from elsewhere who have always wanted to live there but haven't been able to afford it? Either the rents would shoot right back up if we're letting markets function, or the apartments would be insta-filled by a few very lucky people, with a years-long waiting list for any housing that ever opens up. There will always be one more person who will be happy to move to a great climate, top-tier city, unless the rents are obnoxiously high.