Musical instruments are one area where "services" are quite valuable. Anyone with enough time and effort could learn to play entirely on their own and maintain (or build) their own instrument, but for many people it makes sense to take lessons and to pay someone to repair or adjust their instrument as needed. This is one reason why guitar shops are at least partially protected from being driven out of business by Amazon: most have a guitar technician on staff who can troubleshoot problems and fix things.
Hush! Don't speak of such things, or before you know it there will be DRM enforced IoT dongles with 4G cellular radios, requiring a subscription plan and annual fee before the guitar pick-ups will serialize their signal to a 1/4 inch patch cable.
