This is something that keeps me worried at night. Unlike other historical artefacts like pottery, vellum writing, or stone tablets, information on the Internet can just blink into nonexistence when the server hosting it goes offline. This makes it difficult for future anthropologists who want to study our history and document the different Internet epochs. For my part, I always try to send any news article I see to an archival site (like archive.ph) to help collectively preserve our present so it can still be seen by others in the future.
Long ago the saying was “be careful - anything you post on the internet is forever”. Well, time has certainly proven that to be false.
There’s things like /r/datahoarder (not sure if they have a new community here) that run their own petabyte storage archiving projects, some people are doing their part.