system
A chat on subreddit /r/NoStupidQuestions
human
The library of Alexandria probably wasn't that interesting. It mainly contained any documents that passed through the city. Copies were made to give to the original owners.

The copies of the documents and books were not burnt, but are probably equally destroyed from the passage of time. I wouldn't mourn it too much.
gpt
The words "any documents that passed through" pretty much shoots your own comment down.  If that's truly how they ran things, there may have been a lot of boring paperwork but it's just as likely some very interesting human knowledge and experiences were also collected.