Part of the reason rents are high in SF is BECAUSE of rent control (regulating rents). You're just creating scarcity. Developers aren't going to want to take massive losses and haircuts (and neither would you) to build in rent-control areas. It drives up prices all around because there's less real-estate. They've studied this to death. It's a terrible idea
Rent control regulation is great for tenants, which means it's great for keeping people housed.
If that means being a landlord isn't lucrative enough, that's fine, the government can absorb that capacity and build social housing instead. There's no reason the private market should be allowed to monopolize rental housing.
Policy has kept housing expensive in SF by not building enough supply, by not regulating rents, but not building better public transit infrastructure.
And it's the rich advocating against affordable housing. And they made their money through tech.