Maybe a software-esque “right to repair”

Sounds pretty close to what the GPLv3 does, doesn't it?

Can you elaborate? AFAIK the GPL just naively enforces that something needs to be and remain open source. How can it turn closed source into open source?

The problem is that the software is most likely not composed by them in any meaningful way. If you take apart any proprietary firmware and controlling application you are almost certain to find boilerplate code provided by the chipset vendors (protected by NDA) glued together with other code from other vendors with a GPL violating Linux backend.

Recent example: I patched in to my 3D printer's mainboard using a TTL to USB and opened up putty and guess what shows on the console?

> Linux version 3.4.39+ (zhanglei@ubuntu Revision:543)

* https://pastebin.com/CPB7RBdK

That's less of a problem for a hypothetical law requiring either longer-term maintenance or enabling users to perform that maintenance themselves. Manufacturers would just have to make adequate contractual arrangements.

That would be a great way to guarantee that nobody builds hardware in your country.

It would also do absolutely nothing in this situation where the product already comes from a foreign country.

Maybe if it's a tiny country that makes up virtually no market share. If it's a major market like the USA companies will find a way to comply with the laws to continue marketing their products.