AfaIk that’s not entirely true, e.g. Debian is changing the system time from 32 bit integer to 64 bit. Thus I assume other distros do this as well. However, this does not help for industrial or IOT devices running deprecated Unix / Linux derivatives.
industrial or IOT devices running deprecated Unix / Linux derivatives
This is my concern, all the embedded devices happily running in underground systems like pipes and cables. I assume there are at least a few which nobody even considered patching because they’ve “just worked” for decades!
Or like… PLANES! Some planes still update their firmware using floppy disks