The basic skills for this are taught in Electrical/(Computer) Engineering. In fact depending on your college you may end up writing a instruction set emulator lol. So it's not something that requires a 20 year career experience background.

It just takes a lot of dedication and time/energy to reverse engineer. People basically do it as a hobby. Usually the most hobby interest is nostalgia vibes from old stuff but even getting new stuff to run is done for the mental excercise fun