I've been interested in 3D printing for decades, and always felt it'd revolutionize a lot of industries, if not all of them. At some point, once speed, costs and materials all match up, I suppose it's possible most manufacturing will be printed.
Outside of medicine, one of the industries that I've always felt would benefit is auto parts. One day you won't have to wait for a part, especially plastic or electronics (sensors, etc.) -- you'll just call Advance and they'll print it in the store. Saves on inventory, and as long as there's a (correct) file for the part -- regardless of the model or make -- you'll always be able to get it.
If I had the money or the time I'd try to get that started...
3D printing is, IMHO, the only way we get off our addiction to cheap Chinese goods.
I have owned and worked on friend's 3D printers for quite a few years now. I have designed and printed useful things and printed broken parts that were not available for purchase. They are cheap... There really is no good excuse not to get one and learn about them with hands on experience, which is far more valuable than anything that you will ever read about.
You should also check out
to see the types of projects that others have posted that you can print without doing any of your own design work. There might even be a project or two that you would be interested in printing or modifying and then printing.
For fun I modified this blower project
https://www.thingiverse.com/thing:135718
into a gear box that spins a bicycle dynamo with a bridge rectifier can charge batteries much quicker than most similar hand cranked chargers that you can purchase. I also designed a bolt on venturi from the ground up that I used to convert our generator to natural gas. It is more efficient and much cheaper than ones that can be purchased. I cannot tell you how many items I have been able to print replacement parts for that would have been thrown out.
Here is a printer which is not the cheapest but has nearly 9000 mostly positive reviews and is basically open source meaning that you can replace parts as needed with generic pieces, and print with many types of inexpensive and easily available filaments.
https://www.amazon.com/gp/product/B07GYRQVYV/
Here is a cheaper one if your budget won't allow you to go with a name brand.
https://www.amazon.com/Voxelab-Structure-Certified-Removable-8-66x8-66x9-84in/dp/B09BNG5884/