I think it’s important to understand that if the whole Internet just shut off in an instant, life as we know it would cease to exist. I’m not talking about a cultural change. I mean millions of people starving and freezing to death because literally everything you take for granted today is ordered, scheduled, and delivered using the Internet. That means no food deliveries, no fuel deliveries, no imports or exports, no trains, trucks, or planes moving, no payments or money transfers. Nothing. Oh, and all the emergency services that you’re going to need will be unable to respond because no phones and no communication from dispatch centers. We don’t know how to do business without the Internet anymore, so if it goes away, there goes your way of life. Building that back to the “old way” will take way longer than you or your neighbors are likely survive competing for essentially nonexistent resources.
But for those who manage to survive, I would say party like it’s 1899!
If you really want the retro experience, you can get a modern USB version of the original IBM Model M keyboard from Unicomp (https://pckeyboard.com/). I believe these are made on the same equipment that made the Model M back in the day. Buckling spring keys, metal frame, huge, heavy, and loud. Lots of configuration options and the only lights on them are the (admittedly annoyingly bright blue) lock status LEDs. I’ve used an original Model M and own one of these. They’re amazing.