@aho Others have done research on how long it would take to reimplement code bases based on their size and importance, see that research for details.

In short, it's not going to happen, and no one is asking for it to happen. Just evolve like normally and all will be fine. The Linux kernel you run today has almost no code that was in the kernel you used 25 years ago, so why would it have the same code you use 25 years from now?

Except for the tty layer, that beast is almost identical to what was around in the beginning, and probably will outlive us all...