Can you give a specific example of a forum that didn't work? As pointed out
here it's hard to make statements as fora differ :

<https://forum.httrack.com/readmsg/28981/28969/index.html>

The search page seems a little broken, I have to uses Google's
"site:forum.httrack.com" keyword to be able to explore the forum as there
doesn't seem to be visible pagination otherwise.

You could also ask administrators of fora to publish server copies (minus
private data eg. private messages), I used to have a forum and provided a
'backup' for a while which was a 60Mb-or-so copy with 50.000 posts that were
somewhat easy to re-install.

If your library's decision bothered you you could have asked for their
garbage, people's attitude differ, just recently a supermarket here decided to
give yogurt pots for free because they didn't like the idea of throwing it
away. This was an organic supermarket and it is my experience that they
generally care more about solidarity/ecology and the likes, if others don't do
it you still can.

There's a point at which this becomes obsessive, my aunt would gather a
crapton of oldie material with an obvious trend towards melancholic obsession,
people say a lot of stuff in life would you want to record it all?