An archive doesn't make us wiser - what we do with the archive does.
All the information that can be put into the archive should be put into the archive.
Now, I see the following thoughts:
What are the limitations of the archive, such that we need to narrow "all possible information" to "less than all possible information"?
If "less than all information" is required, then a systematic filtering should be applied. High-level answers (categories, personal preferences) do us little good.