With reference to piracy of fiction, do away with geo-restrictions, DRM and vendor walled gardens, and I think a lot of reasons for piracy disappear.

But that's only my guess, based on the move they just made. It appears that a large user base - both downloaders and uploaders - may be of more importance to Z-Lib than the direct income that would come from a donation-only model. None of this would be needed on the dark web. Because then they have a presence on the clear web. I would guess that Z-Lib's current move to provide a common login page with user-specific 'secret' access domains is an attempt to maintain and increase their user base. Domains can be shut down on the clear web, but there is still the dark web out there.

Even if they are for profit, they would have to consider if the decrease in their size - number of users, downloaders mostly - plus the decrease in their uploaders - smaller amount of content - would be worth forcing direct payment from their user base. Making a move to donation-only would probably depend on if Z-Lib considers itself a for profit business, or a piracy for the fun of piracy entity. And an unwanted side effect for Z-Lib would be that their uploaders - the source of their content - would also go down with the user base size. However, their user base would go down if things required payment. They would be getting money directly from their users, not indirectly from advertisers or whatever supports them currently. And initially may look appealing to Z-Lib. A move like this would give pause to even more pirates. Going to a donation-only model, generally known as a paid model, would be even better for authors and legitimate distributors. But giving pause to some pirates would be good for book authors and legitimate distributors. This may give pause to some pirates who worry about giving out their email address, if they don't already use untraceable email services. The next one is donation-only, which we know from the example of other such libraries. It is good to see them to move to login-only stage.

Z library sign on