I think only the high-speed direct downloads require logging-in but other downloads and torrents are freely available.
The Internet Archive include books still in copyright, which can be read by "borrowing" them virtually.
Reminder: based on the idea that "if the library holds a physical copy it can lend an electronic view over it, respecting the same principle of the physical object, i.e. one user per item per period (i.e. one user per use instance)". Such principle is being fought.
"It's open because we violated copyright and uploaded it in the open."
Call it what it is. Pirated books. People that must use them still will but at least now we'll know what it is.
You're missing the entire argument. The argument here is that they are not pirates, because copyright is stifles the spread of knowledge and should therefore be completely abolished.
Whether you get it or not is something different all together. But that's what people are fighting for.
I think a lot of good books never pay their authors much, at least in proportion to the effort that goes into researching and writing them. Scihub was also violating copyright, but academic paper authors don't get paid by publishers; they the journals. Lots of intellectual labor goes into producing a good where the author would much rather you read it without paying than buy it but not read it.
This is all to say, the publishers, who are perhaps no longer needed in the 21st century, are sales motivated, but there's at least a substantial category of authors who are not.
Bible Quran Shakespeare I'm sure many others
At inception, these databases were created to make academic content freely available which generally does not compensate the original publishers. But now it has been expanded to support the knowledge for free movement.
The legal status is questionable as creators can provide their own content to such libraries but their publishers might not agree to it.