shh! do you want lingren to get taken down as well? whether accurately or not, the takedowns is attribute to a sudden burst of popularity due to social media sharing of the site.
Z-library was popular amongst everyone, hackernews is a really niche website. But I believe with that website going down people will start looking for alternatives.
If everything fails, we can always go back to download books through IRC.
But it wouldn't be surprising that such a popular platform would have ads. Z-library was a site for pirated e-books, no?