My target audience is not normal people though, and I don't mean this in the "edgy" sense. The fact that we are having this discussion is very abnormal to begin with, and I think it's great that there are some deviants from the norm who care about the longevity of such projects.
I can imagine many students and researchers hosting a mirror of LibGen for their fellows for example.
Z-Library has been innovating a great deal in that regard. Sadly they are not as open/sharing as LibGen mirrors in giving back to the community (in terms of database dumps, torrents, and source code).
I think Sci-Hub is the opposite since 1 DOI = 1 PDF in its canonical form (straight from the publisher) so neither duplication nor low-quality is the case.
I don't think you've deserved the downvotes, and I don't think it's a bad idea either; indeed some coordination as to how to seed the collection is really needed.
For instance phillm.net maintains a dynamically updated list of LibGen and Sci-Hub torrents with less than 3 seeders so that people can pick some at random and start seeding: https://phillm.net/libgen-seeds-needed.php
> While I'd love to mirror whole archive locally, it would really be superfluous because I can only read a couple of quality books at a time anyway, [...]
I'd love to agree but as a matter of fact LibGen and Sci-Hub are (forced to be) "pirates" and they are more vulnerable to takedowns than other websites. So while I feel no need to maintain a local copy of Wikipedia, since I'm relatively certain that it'll be alive in the next decade, I cannot say the same about those two with the same certainty (not that I think there are any imminent threats to either, just reasoning a priori).
To be clear, I am not advocating for the removal of any files larger than 30 MiB (or any other arbitrary hard limits). It'd be great of course to flag large files for further review, but the current software doesn't do a great job at crowdsourcing these kinds of tasks (another one being deduplication) sadly.
Given the very little amount of volunteer-power, I'm suggesting that a "lean edition" of LibGen can still be immensely useful to many people.
If you are referring to my duplication comments, sure (but even then I believe there are duplicates of the exact same edition of the same book). Though the filtering by filesize is orthogonal to editions etc. so has nothing to do with that.
I can imagine many students and researchers hosting a mirror of LibGen for their fellows for example.