I think it's more like your gen1 wi-fi enabled Philips screwdriver stops working because it's EOL as opposed to because nobody uses Philps screws anymore. Sometimes it's the latter, but not always.

A more direct analogy is right there; your Phillips head screws cam out more easily than Torx. Everyone who wants screws that don't shred as easily moves to that weird 6 pointed star pattern, and your Phillips head screwdrivers are suddenly EOL'd.

Unlike buns, software doesn't deteriorate

It does, especially at the scale of operating systems.

Bugs and vulnerabilities are always being found, with fewer and fewer people in the pool that might even theoretically want to pay for fixing them.

Also, hardware does deteriorate, and the story is the same for adding software support for whatever is currently available in hardware.

> Bugs and vulnerabilities are always being found

none which haven't been there from the beginning