I'm someone who repairs a ton of things, but consumer 3D printers aren't practically useful for the majority of repairs. Injection molded plastic is significant

I'm someone who repairs a ton of things, but consumer 3D printers aren't practically useful for the majority of repairs. Injection molded plastic is significantly stronger than consumer 3D printed plastic (yes, even ABS.) What that means is that if the original part breaks, the replacement will break too. Even if you just go for equivalent strength, the replacement has to be significantly larger and in many cases is simply not possible (as printed objects are quite weak along layer lines.) I'm sure there are all sorts of counterexamples people have posted online, but the evidence is out there. Look at thrift stores or eBay or whatever. You can find plenty of objects repaired with traditional methods (epoxy, fillers, metal plates, glues, rivets, screws, plastic welding, etc) but I have never come across any used items repaired with 3D printers. Perhaps in five or ten years we'll all be printing high strength nylon or continuous fiber parts at home, but for now I'm chalking this one up to marketing.