Incidentally, you can observe the same effect, however with a different delay, with subsequent releases of macOS versions: each time the support for some device

Incidentally, you can observe the same effect, however with a different delay, with subsequent releases of macOS versions: each time the support for some devices is dropped, their price drops, too, even though the hardware is inherently the same before and after announcement. In the past, I used these MacBook Pros from 2012 to install additional memory and replace small HDDs with large SSDs but today this is no longer possible. Still, some perfectly good hardware can be bought cheap only because Apple doesn't support it. And if you used it back then, you can install perfectly functioning software on them like, say, Logic and use it for many years to come as an audio workstation even if Apple doesn't want to support it anymore.