Or, it’s because whoever is doing this hates freedom of information and historical evidence. There’s a long list of powerful people and governments who have the resources and will to carry out these attacks.
Cyber warfare is real, and the Internet archive is a museum and library of culture and truth. It provides evidence and context to our past.
As in conventional war, it is valuable to the amoral to destroy culture and truth in order to control it. Many would like to kill that to supplant it with their version of events that can’t be refuted with evidence.