This is horrifying, terrifying, and sadly well-known even to those who superficially monitor such things.
Popular media: More than one US film/tv studio has "lost" or "suffered a mysterious fire" in un-digitised archives, destroying the lot, during battles to preserve. The BBC sued Bob Monkhhouse for preserving material it destroyed. In Britain, it has been no better. Fans of the British TV series "The Avengers" can only see old episodes because armies of previous fans descended on rubbish tips and, at great risk to themselves, collected as much film as possible.
General history: Places like the John Ryland's Library and the British Library have suffered with rescuing archives at risk of becoming submerged or destroyed by mould. The Archimedes Palimpsest was partially destroyed by one collector filling in the pictures with coloured pens and by another collector allowing the book to be severely damaged by mould.
The National Archives have mysteriously "lost" a great many files over the years and are only digitising those they've retained at an incredibly slow rate. I know because I've personally forked out several hundred to get just two scanned, all because politicians far prefer frippery to archiving. We've absolutely no idea how many of the manuscripts held in other archives are still in usable condition because nobody bothers to check.
It's not just limited to archives, of course. The US has, over the last couple of decades, demolished numerous buildings within the US that are over 300 years old because malls produce profit and ancient structures don't. (They also then complain they have no history...) The Space Shuttle is to be taken to Texas for a PR stunt, which will require it being dismantled and those things aren't designed for that. There is no guarantee any of it will survive the journey. All because PR matters and preservation does not. Other countries? The Louvre... well... probably best not to talk about that utter disgrace. In Egypt, 3000 year old gold artefacts are routinely melted down so the conservators can pocket some extra cash.
It's at times like this that Kenny Everett's general comes to mind.