I grew up in California, went to Berkeley, and worked in there for years, but I couldn't stand the backwardness of California's homeowner cabal anymore and moved out of state. In my new state, there's no rent control, no NIMBYism, and homes and neighborhoods are beautiful and affordable. Sure, there's more room to grow here, fewer people, and a smaller economy, so it's not a completely fair comparison, but take a mom…
To say it's not a fair comparison is putting it rather lightly. Those are the three biggest factors that influence pricing.
Your entire premise is that Bay Area rents are high because of an excess of "completely undeveloped land". That defies credulity and is far from evident from satellite imagery.