I mean there are huge home builders in the USA like DE Horton. Then there are local builders who are basically smaller "startups". If you mean a "tech startup

I mean there are huge home builders in the USA like DE Horton. Then there are local builders who are basically smaller "startups". If you mean a "tech startup", where exactly do you think software would bring an economy of scale? To build you largely need local expertise, land, planning permission/permits, infrastructure etc... these are time intensive things.