The internet has always been fragile like that though, it's not a new thing. Even more than a decade back there were those encouraging saving local copies of web pages for any content one found worthwhile, rather than bookmarking it, since there's a likelihood of the link/content disappearing, which time has shown to be a smart idea given online archives aren't always reliable[1].

The same is true (perhaps moreso) for audio/visual media online.

[1] It takes someone else to first know about archive sites, consider archiving a link pre-emptively either manually or in an automated way, which doesn't always occur. Then one problem is if a link changes a version may have been archived at the old link but the new link doesn't show as being archived (sometimes redirects are in place, other times not). Another issue is archive.org respects robots.txt and webmaster requests so crawls can be retroactively made non-public (archive.is is a bit different but there's so little known about who operates it that it's unclear how reliable it is for long-term reference).