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.
It’s still fairly new, I’m confident we’ll see fediverse crawlers before too long. Especially with all the attention it’s getting and more developers turning their interests here. I also saw some talk about instance mirroring that would allow backups should an instance go down. Things are in motion.
Absolutely a problem at the moment but I’m not too worried for the future tbh.