But many of the products we buy, especially for Christmas, cannot become obsolescent. The term implies a loss of utility, but they had no utility in the first place. An electronic drum-machine T-shirt; a Darth Vader talking piggy bank; an ear-shaped iPhone case; an individual beer can chiller; an electronic wine breather; a sonic screwdriver remote control; bacon toothpaste; a dancing dog. No one is expected to use them, or even look at them, after Christmas day. They are designed to elicit thanks, perhaps a snigger or two, and then be thrown away.
Utility isn’t what you think is useful. It’s what other people think is. And you don’t get to impose your idea of what utility is on other people.