I know a guy who runs a multi-million dollar business making replacement parts for a particular type of business machine that you find in a lot of places. There are only a few OEMs and they all stopped making a similar (critical) component for their older models.

He was originally in the business of repairing these machines and then discovered he could no longer buy these parts from the OEMs so he learned CAD and CNC and injection molding and started making them a few years ago. He has a 3D printer for prototyping, but he needs to injection mold part of the final product because there is no filament in the particular material that he needs. His business has transitioned from repair to manufacturing and now he mostly sells replacement parts to other repair shops.

I don't want to disturb his business by talking about it in detail, but the point is that I think there are and will be many opportunities around repair parts that manufacturers are unwilling to provide because they'd rather be selling new machines. Aside from the environmental impact, that's fine since there are many people who won't go the repair route, and then there's a secondary market for those who will make parts and repair the machines.

I used to know tool and die makers that did that back in the day. Sadly, a lot of manufacturing was sent off to China. I assume there are Chinese people doing similar things.

I'm willing to bet the quality of a lot of these is shite, though. Plus people in the US would most likely want to buy from a seller in the US (faster shipping + implied better quality).

There is a solution to so many problems here (creating usually unavailable parts for machines/devices/products) but the problem is knowing which parts are in demand and currently have no supplier.

A maker would need to have an interest or hobby in such a device & discover a need for the item for it to come into fruition. But just think of how many general 3D printed parts could be printed as solutions for so many products out there that are going unmade.

I meant that there must be Chienese people doing the same thing people used to do here when domestic factories a thing.

I was not commenting on the quality of the work. BTE, saying the Chinese quality must be automatically shite is a ridiculous idea.

Not all Chinese stuff is bad, but there's so much bad stuff that it's hard to know what's good. "Chinesium" is an accurate description of the situation.

Same with American made products. Have you driven a Chevrolet lately?

In the case of American-made products, it's easy enough to do the research to determine if a product is good, or even try it before you buy. I don't know how good Chevys are these days—the newest one I've driven is a 2005 truck—but they're a known entity and you can test drive one for free. Ordering something online from China is a stab in the dark.