One problem I see with annas archive is that there is a tendency towards older books. Now I do understand this for many reasons, but ... I recently read a book about steel construction in 1932, just for curiousity. I wanted to find a more recent one - did not even have to be, say, 1990 or 2000 or some such, but I simply could not find any (well, perhaps english speaking, but this is also a problem in that non-english languages are VERY underpresented in general).
I hope they can fix this in the long run. We need to preserve digital information on a much broader basis.
There's nothing AA could "fix" here, this depends entirely on volunteers uploading the books. Your best way to help is to buy the books yourself, use a book scanning service (eg. 1dollarscan), and upload it to ZLib/LibGen.
You can also make a book request on ZLib, that way someone else will be able to do that for you if they want to
I hope they can fix this in the long run. We need to preserve digital information on a much broader basis.