Interesting, and fits with what I've experienced. I worked a few months for a company that used "advanced 3D printing" for prototyping and mold/tooling construction. It was faster for the parts designers to knock out a prototype part for the customers in country, then send the documentation and STL file to the factories in Japan, Taiwan, and China for tooling and production. According to the engineers I worked for/with, it cut down part order turn around from 2-3 weeks for tooling and 2-3 months for first articles to 2-3 weeks for first articles from the factory. I learned how to make STL files for the printers while doing their English documentation/translation work. I got a secondhand printer - a MakerBot Replicator - and played around with it for weeks. It was really great for making all kinds of useless tchotchkes and a few "can I print a replacment part for this" experiments. I sold it when I moved. It's a wonderful experience to produce stuff, but the average household doesn't have the need to have a 3D printer in house. Something like the "maker spaces" or even public libraries are where they seem to flourish, not in every home. Being able to design a part and go reserve a printer and get the part made overnight is a great modern convenience for tinkerers. I think the last thing I had printed was a mounting bracket for a (network) switch for under my desk. The first party ones are about $10 and ship within 2-3 weeks, whereas I designed mine and had it printed and installed in under 36 hours.