Lawmakers
are not technologically inclined. Their job is to administrate, not understand the technology they use to help them do this.
So, the best way to solve the right-to-repair problem is not lobbying, it is education. Educate the lawmakers so that they understand the bollocks that fill the anti-rights cause, and call them out on it. They don't need to graduate with an electronics degree but, for example, set up a very small repair in front of their eyes so that they understand that replacing an SMD does not mean accessing the source code, or pretty much any code at all (unless you get anti-repair tech like Apple's serialization, then show them why it hurts the consumer's interest in long-term ownership and what can be done without violating copyright laws).