Furthermore no one is arguing that density drives down prices. You’re arguing against a straw man here. People are pointing out correctly, and in line with all housing economists, that constraining supply raises prices.
First, it's 100% the right of communities to establish - and change - zoning laws. Those can change after a property is acquired.
More importantly - this issue is not about people having zoning changed from under their noses, rather, it's about developers interested in creating different kinds of accommodation then those that have previously existed under existing rules. They knew what they were getting into when they bought the land. This is not 'zoning rug pull' kind of activity.
Second - this push is mostly about issues affordability. Cali legislation was driven by it.
"Governor Newsom Signs Legislation to Increase Affordable Housing Supply and Strengthen Accountability, Highlights Comprehensive Strategy to Tackle Housing Crisis" [1]
What you are calling a 'straw man' is literally 'the man'.
[1] https://www.gov.ca.gov/2021/09/28/governor-newsom-signs-legi...
That’s not the argument I’m making. I’m saying that communities have no right to arbitrarily block uses that comply with existing code. This is a rule of law issue. SF has admitted to violating state law which supersedes local law.
Again, my point is that YIMBYs are not making the claim that density per se drives down costs.
But yes arbitrarily restricting housing supply does create affordability issues. The NIMBYs of SF in the end if they win will find that they have created a museum of SF.
Ok, well it is also the right of the state to make laws and force these communities to change, under threat of government force.
Which is what is happening right now. There are going to be lawsuits that force communities to allow people to do what they want, with their own property.
Go win a state election if you disagree.