Prepackaged foods list their ingredients so consumers know what they’re putting into their bodies.
My rule of thumb is not to eat anything I cannot pronounce or if the list sounds more like a Gilbert Chemistry set than food.
Stereo equipment manufacturers have no such rules though many tout the good stuff (and generally keep quiet about the ho-hum parts).
The more organic the parts the more likely a manufacturer is to list their ingredients: vacuum tubes, film capacitors, MOSFETS, JFETS, GaN FETs, FPGAs, precious metal connectors, high purity wires.
Other than food, automobiles, furniture, clothing, and high-end stereo equipment I can’t think of many other products that care to list their primary ingredients. Perhaps this is because consumers don’t care?
More likely it’s because it’s not important. I don’t really care what this computer is made of nor do I give a rat’s ass what type of rubber or plastic goes into the tires on my car.
I do care what the ingredients are in my speakers and electronics because I believe their composition plays a major role in the quality of music I am expecting to enjoy.
Not every FET, tube, or carbon fiber cone sounds best but it certainly is a good starting point from which to form an opinion.