Those biorobots are limited to what a human is able to do. A Roman slave can only lift as much as the strongest human. A forklift can lift far greater weights, a printing press can make far more copies than an army of scribes could produce. their economic conditions and culture had them stuck in a local maxima, but what a maxima it was. What are we currently stuck in a local maxima because we're hamstrung by economic conditions and our culture? housing and zoning seems to be a big one.