Not everything, just things hooked up to long enough wires to induce significant current. Pretty much just the power grid and the copper communication networks. For instance, I've got a raspberry pi hooked up to some solar panels handling some gardening stuff for me, it'll be just fine.

Editors are irrelevant to that conversation, but people who are accustomed to relying on stacks with many dependencies will definitely find that they struggle more without the internet than people who keep their dependencies minimal. And it's not a cherry picked example, there are all kinds of cases where minimal dependencies = resilience. It doesn't mean you have to go around using punch cards or something, it's really just the emotional attachment to complex tooling that I'm calling out as a hazard here. You end up cultivating skills that are easily invalidated.