The land value and carbon taxes are key here. The carrot is people seeking better, happier lives and developers seeking to turn a profit - the lower bullet points serve to allow these carrots to be attained. But the taxes are the stick. And people tend to move a lot faster when you beat their asses.

A land value tax removes the incentive to speculatively hold onto land. Instead, it charges landowners a heafty fee to hold onto valuable land in or near walkable areas, which sends a clear message - build something (like housing or a business) that will make good use of this valuable land, or give it to someone who will.

Of course, this will light the fire under some asses. Owning valuable land is still valuable with a land value tax - it is just that the value is in the potential profit to be made, which is only realized if you build something. So expect land owners to be ready and willing to pay big sums to import the labor and materials necessary to get their land to a profitable state as soon as possible. And this would also be a strong incentive to use existing unused building space in walkable areas. All those luxury apartments with outrageous rents sitting empty would see steep price drops as owners scrambled to get someone in the door to make the building profitable. Same with all those empty storefronts which have been vacant as the landlord lazily searches for the "perfect" tenant. And all that office space in downtowns, unused since covid? Expect it to be rapidly retrofitted into affordable housing.

So while rents in walkable areas are screaming downwards, the carbon tax creates an additional incentive to move there. Of course, we pair the tax with a dividend, so an average person is actually making money from the tax - but the incentive is clear: the less carbon you emit, the more money you make. Which encourages people to choose less carbon-intensive forms of housing and transportation. Which means more apartments and cycling, and less detached homes and driving.

but there’s no way that’s sustainable

Why not?