I’ll go straight to the point:
- Piracy is useful to bypass regional frontiers and access to censored content
- Piracy is helpful to watch content without supporting it if you consider it not worth of it
- Piracy might be helpful for content preservation and survival
- Piracy is useful to ACTUALLY evaluate whether to spend money on some digital content or not
- Piracy is sometimes the only way to actually own DRM-protected content
At least in the EU there are plenty of alternatives. Big book retailers often have an ebook download shop as well as publishers running their own ebook stores. Google Play books, iBooks and others are also around, although much smaller than Amazon. Ironically it’s mostly the indie authors that are only on Amazon because they made it “easy”.