When the blackout the only protocols which worked fine where IRC, Gopher and Gemini. I could resort to using IRC->Bitlbee to chat against different people of the world, read news and proxy web sites over Gemini (the proto, not the shitty AI). But, for the rest, the average folk? half an our to fetch a non-working page.
That with a newspaper, go figure with the rest. And today tons of projects use sites with tons of JS and unnecesary trackers and data. In case of a small BGP attack, most projects done with LLM's will be damned. Because they won't even have experience on coding without LLM's. Without docs it's game over.
Also tons of languages pull dependencies. Linux distros with tons of DVD's can survive offline with Python, but good luck deploying NPM, Python and the rest projects to different OSes. If you are lucky you can resort to the bundled Go dependencies in Debian and cross compile, and the same with MinGW cross compiling against Windows with some Win32, SDL, DX support but that's it.
With QT Creator and MinGW, well, yes, you could build something reliable enough -being cross platform- and with Lazarus/Free Pascal, but forget about current projects downloading 20000 dependencies.