This is not unique to software. There's no "free&open ball bearing" design out there, let alone for a machine capable of making them, even though the modern world couldn't work without them. The only people caring about ball bearing design are technical minded people already working in the field.
Same as for a thousand other fields essential to operating the modern world. Nobody has time to learn them all, so we specialize.
The GVCS is a totally different beast than open source software. It's been around for at least two decades now, and has been making very little progress in the last ~15 years. It's trying to reproduce the most visible products of mechanical engineering without having a firm grasp of what is needed to get the supply chain working.
Notably lacking from their toolkit is anything large (no refineries, no blast furnaces, no glassworks for making window panes, etc) or anything needing high precision or high purity (medicine, ball bearings, optics, high quality metals, etc). It still assumes the rest of society will be around to source those materials from.
The GVCS is like if FOSS only ever produced leftpad libraries and never a linux or a postgres.
The problem is the GVCS is already bumping against the OSHW curse even for the smallest items: replicating one unit costs real money in materials and processing and if you fuck up, a new version costs real money too. But in the last 15 years, the niche is shrinking - you can get a decent new doohickey from China whereas previously you would have to hope for an ex-first-world or ex-Soviet cast-off.
A 500 million glassworks or foundry is just that times a million (literally). And technology has never stopped - no one would spend a hundreds of millions to build a new plant on a 20-year old design.
Oh I totally agree. One reason open source software is so "easy" is that it costs virtually nothing to share something you made, or to take something someone else shared and build it yourself. The potential pool of hobby contributors drops off drastically even for $10 gadgets, let alone for anything 10k and up.
Even their own manufacturers don’t know what’s in a bearing assembly they manufactured ten years ago, all they can do is sell you a new one with the same spec. Rolling element bearings are specified by application; shaft diameter, load direction, and so on. Manufacturers change important things about bearings, like how many rolling elements they have, without necessarily changing the part number. It’s worse than closed: after some time has passed, nobody anywhere knows how it was made.
Software is unique in a few ways. It has the ability to spy on us, to be insecure and against our best interests if an attacker gains control. It can also lock us in in ways that are harder with just physical objects. Infact printer ink lockin happens using software not e.g. the shape of the cartridge.
There are some attempts at things like this: https://www.opensourceecology.org/gvcs
They're usually very hard to get share because machine manufacturers can smash out cheaper things via processes like castings, mouldings and stampings, then eventually lock down spares (or just don't bother).
The open source option basically only be worse (but maybe more repairable) and/or more expensive than the alternatives, except when there is no alternative in the market. And China is providing so much mid-grade affordable and fairly functional stuff there often is an alternative even in the most isolated places. In 1980, getting a decent lathe in some town in, say, Angola might have been basically impossible. Now, it's still not cheap, but it's not completely impractical. If you can get bearings and induction-hardened shafts you'd need to DIY, you can get the whole thing, and maybe even cheaper.
It's a bit depressing, because of course I want to see the world flooded with high-quality, modular, very standardised, re-usable, repairable, hackable items, but that approach has a limited market in reality.