Piracy does not hurt sales because it has a lot of friction. There have been zero studies on piracy in a low friction environment, because there was no need. Such as in countries where pirated Video CDs where endemic and not policed, it was completely obvious and distributors didn't even bother putting product onto the market. Or back in the days where mp3 music sharing apps became mainstream and got integrated with music players. Or when Popcorn Time looked likely to replace every streaming service in existence. If something like the Internet Archive Library became low friction (click the button and you are reading on your e-reader), and declared legal (avoiding social stigma), do you honestly believe this would not become the default and normalized way of 'buying' books?

I think there is an important difference between (1) being able to buy the same (DRM free) content supporting the authors and (2) the copies on the Internet Archive or the likes of it being the only source available.

I think many will choose the former but there are so many cases where there is no option provided.

Everyone forgot about limewire and the masses installing every trojan known to man.

Limewire made it easy, so people used it.

The same would be true today if assume.