Over the past 20 years or so I've become convinced that people alone are not yet smart or skilled enough to produce this kind of technology. The technology is absolutely achievable. The most compelling example of this kind of "tech" is biology itself - living, growing things. Cells turn nano-scale work into macro-scale products every single moment of every day. People, working together under a large-scale, coordinated effort can eventually create machines capable of this same feat. But...I think we will need AI assistance to get there. My hope is that an AGI can assist us on the path to this goal within the next several years. But without AGI, I fear it will be a long time.