Perhaps, because those items have dated titles, that must be legally transferred. If an electronic component has a serial number and it’s manufacturer is still in business; they can tell you, within a certain(generally limited) time-frame, when it was built. Because of the model numbers/iterations/serial numbers of my components; I know(within a year) when all of mine were built(just took a little research). Some of my tubes(most of which were made in the Forties, Fifties or Sixties), can be traced back to their locations of origin, as well as month/year, via coding. Regarding tubes; that info can be very important. With most components, I don’t obsess. Apparently; most others haven’t been obsessing either, or- electronics(as well as the vast majority of other consumables) would have been dated(and perhaps, come with Certificates of Origin), for decades.
