Perhaps the darkest part of the "dark ages" for the people who were living through it was encountering things made by a civilization before them that they were unable to repair or recreate. The Roman Empire had a large number of technological innovations that were lost after the empire fell. It took a very long time for technology and the societal knowledge needed to create it came back to a level on par with what was seen centuries earlier. Even then things from the past were forgotten.

Modern people tend to have a lot of ignorance about these matters, after all we have smartphones so people get absurdly complacent. I remember someone saying "we have the library of Alexandra in our pockets these days", but that library burned down and we don't know what was actually in it. We certainly have more access to information than before, but that doesn't mean we have access to everything that came before us, it also says nothing of the quality of that bulk information either. We are sold constant propaganda about how now is so superior to the past and that we aren't to think anything positive of the past. When people emotionally engage with this they lose their perspectives with respect to what happened in the past. This propaganda is mostly designed to destroy traditionalism but it comes at the cost of destroying much of the wisdom of the past at the same time.

In this moment in time, like all others, we are forgetting things that existed before.

Keeping society going is a constant battle, remembering useful things from the past is also a permanent battle. I think by documenting some things people knew in the past it helps preserve these ideas. Some of these ideas are great and worthy of remembering as a template for what to do, some of these ideas are terrible and are worthy of remembering as a template for what not to do. At the very least appreciating that knowledge can be lost is worth deeply understanding so we don't lose the knowledge we have fought so hard to build.