We'd live in the Diamond Age. The molecular nanotechnology vision of the world would be true. Eg. we could create any material with the characteristics we wante

We'd live in the Diamond Age. The molecular nanotechnology vision of the world would be true. Eg. we could create any material with the characteristics we wanted. Uncertainty wouldn't matter because there would be no compound uncertainty / decoherence. If some sub-process step in mnt fabrication failed because of inherent uncertainty, it could simply be repeated until it worked. We'd also understand how to build the tools to do this.