I completely understand marking the software that controls drinking water as critical infrastructure- but at some point a state based cyber attack that just wipes wikipedia off the net is deeply damaging to our modern society’s ability to agree on common facts … Just now thought “if Wikipedia vanished what would it mean … and it’s not on the level of safe drinking water, but it is a level.
That someone would need to restore some backups, and in the meantime, use mirrors.
Seriously, not that big of a deal. I don't know how many copies of Wikipedia are lying around but considering that archives are free to download, I guess a lot. And if you count text-only versions of the English Wikipedia without history and talk pages, it is literally everywhere as it is a common dataset for natural language processing tasks. It is likely to be the most resilient piece of data of that scale in existence today.
The only difficulty in the worst case scenario would be rebuilding a new central location and restarting the machinery with trusted admins, editors, etc... Any of the tech giants could probably make a Wikipedia replacement in days, with all data restored, but it won't be Wikipedia.