> This line of thinking is what leads to situations like San Francisco, where price controls on housing lead to few developers willing to build there.

Not sure what "price controls" you're talking about, but the reason it's expensive to build in SF (which reduces the appeal for builders) is zoning, the byzantine planning process, the ability of local residents to effectively block or delay projects, and weaponized environmental review.

> Do you want to invest tens of millions of dollars into building an apartment with zero expectations of making a return?

Building housing doesn't need to be an investment opportunity. In a better world, I'm sure there would be plenty of people who would be happy to build housing with only enough profit to pay employees a comfortable wage. These sorts of people don't have the ability to break into the industry, though.