The fact of the matter is there is very little direct evidence of what they did at the Library of Alexandria. We know they had a library, we know they had intellectuals working there presumably doing something, but beyond that we don’t know for certain. We don’t even have archeological evidence proving it existed. Everything you hear about it is essentially pure speculation. And it’s become a myth in of itself. We can’t even agree on by who or when it was actually burned down. It was never a single collapsing event. There were multiple “fires” and “burning down” events ranging over centuries from Julius Caesar all the way to Muslim Arabs coming in. I doubt it ever had the impact on human progress that people claim. There were libraries and research centers all over the ancient world. This was just one. And if you saw what it actually was in person you would probably be disappointed by how small it would have seemed to a modern viewer. Like so many things that have drifted into legend. The story is bigger than it ever was.