I’m not sure if #ebooks mirrors Libgen. I wouldn’t be surprised if they copy from each other.

It is unclear to me what's the method to upload to #ebooks. I've uploaded some obscure books to Libgen in the past, so I checked whether they're available on #ebooks, and they're not. So... they don't mirror each other. I checked both UnderNet and IRCHighway, and the latter even directed me to these websites in case I'm looking for textbooks. It doesn't seem like an adequate replacement for LG, at least for my purposes.

I have allergies against ads, countdowns, etc. The interweb is polluted with that stuff and so are most piracy sites.

As I've said, this is not a big issue with the sites listed on the uptime tracker I linked. Libgen.is and Z-library have neither (the latter has daily download limits per IP), AA has a countdown (not always), and libgen.li has ads (which I had no idea about until I saw other people mentioning it, thanks to uBlock).