Production is always judged by how much time it takes for raw material to become finished parts. Additionally that is split between 'operator time' (person required) and 'machine time' (just the machine running).
'Operator time' is a function of how skilled the operator has to be (machinists cost a lot more than technicians).
'Machine time' is a function of operating cost and depreciation.
So anything that shortens those times, or cuts those costs lowers the cost per part. Parts "have" to cost less than a threshold amount to meet the sales price of the final assembly + margin.
That is all basic manufacturing. The key is that costs have typically been reached by doing things in volume with 'tooling' (investing in dies and jigs to configure the machine to easily make the one part). That essentially makes the production line 'single use' while it is tooled that way.
These guys are proposing that they can make metal parts at the same cost as the tool and die folks in smaller quantity and with no setup costs. That changes several things;
1) You can make warranty/repair parts "on demand" so cut the cost of making a million widgets and storing them in a warehouse.
2) You can make 'small runs' of products for more specialized markets at a price that the market will accept.
3) You can support more variations of a given product without your spare parts inventory exploding.
4) Production can be parallelized from small scale shops so a large 'mega factory' isn't needed, instead you can get a dozen shops with this gear to work in parallel to meet your production target.
If they can pull it off, it really does change a lot. If they can get the costs down further it opens the possibility of domestic delivery of parts from a certified vendor rather than a warehouse somewhere.
In terms of second order effects, I think one interesting angle is that low-setup manufacturing makes ip / copyright in the STL files more valuable.
If you don't have the design then a human needs to spend a bunch of time dialling in the geometry.
I can imagine manufacturers wanting to find ways to "DRM" spare parts. One way to do that might be to make it more costly to produce designs from first principles. So having for example specific complex bits of geometry that ultimately force you to license the authorised design if you want to "economically" fab the part at low volume.
The fact that the company shipping them wants to be in the news?
More seriously: the main innovation here seems like accelerating the print volumes and decreasing the per-item cost to the point that this could be used in production rather than just for prototyping. That's a kind of "mainstream", though still on the high-end business side, not consumer.
Mostly cost & benefits over existing metal 3D printing technologies.
Current metal 3D printing machines cost well over $1 million, and have some significant caveats for part design. Due to the residual stresses in the parts, supports structures are required for many part geometries. This means your parts that have been designed to be unmachineable, now have support structures that then need to be machined off. The easily removable supports are a huge win for Desktop Metal here.
Repeatability has also been an issue in metal 3D printing. This is partly due to the nature of the sintering/melting process, but mostly because the majority of parts produced on metal 3D printers are actually designed to be manufactured using another process. I have higher hopes for the production system than the studio system for improvements in that area, but remains to be seen at this point.
