Google never did make backups of the Internet, why are we pretending like they ever did? Cached webpages were a basic workaround for third-party website downtime; a guarantee that you could reliably see the information you searched for, even if the linked site was down. It was nothing more than a snapshot of the webpage their crawlers saw, where older copies are permanently deleted with every new crawl of the page.
It was never an archival effort, it was a rotating cache. If you were under the impression for all these years that Google was preserving Internet history, I don't know why, because Google never claimed to be doing that. Maybe it's time to reevaluate any other altruistic things you're assuming that mega corporations are up to...