> If you can't make CPUs and you can't keep the internet up, where are you going to get the equipment for enough "private peering or Sat links" for the privileged?

Storage. You only need a few hundred working systems to keep a backbone alive. Electron migration doesn’t kill transistors if they are off and in a closet.

> You need CPUs to build optical media drives! If you can't build CPUs you're not using optical media in 30 years.

You don’t need to make new drives; there are already millions of DVD/Bluray devices available. The small microcontrollers on optical drives are on wide node sizes, which also make them more resilient to degradation.

> they're definitely f-ing going to have been able to repeat all the R&D to build a 68k CPU in 30 years (and that's assuming you've destroy all the literature and mind-wiped everyone with any knowledge of semiconductor manufacturing).

If you read the post, the scenario clearly states “no further silicon designs ever get manufactured”. It’s a thought experiment, nothing more.