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.
even beyond what you said, even if we had a global blockchain based browsing system, that wouldnt make it easier to keep the content ONLINE. If a website goes offline, the knowledge and reference is still lost, and whether its a URL or a blockchain, it would still point towards a dead resource.