If an artificial town could be self sustaining, a lot of the benefits you want explained might just happen just by not having legacy stuff. E.g. the roads, and

If an artificial town could be self sustaining, a lot of the benefits you want explained might just happen just by not having legacy stuff. E.g. the roads, and road rules could designed with new forms of transport in mind. Housing might (initially!) be cheaper because zoning requirements don't force prices up. There's wishful thinking in all of the above, but I think that is concentrated in the wish that such a town could get off the ground at all. But about the only kind of artificial town that I find plausible is when a state wants to build a new capital -- and that will immediately be a gravy train for parasites who want to crank up the costs.