One reason we have megaprojects is that permits and regulations are so time-consuming that small builders (who face the additional hurdle of coordinating with each other) can't afford it.

The shutdown in housing construction has been so extreme and long lasting I'm of a mind to just let the big guys build. Get out of their way. At least the burden of proof is on those proposing other approaches to show convincingly that their plans are not slowdowns in disguise.