Book machines

I hate these machines that have the ability to hold several books (like kindle or ebook)
First, you are spending $100 for a machine plus $3-10 for ebooks when you can get a FREE library card and get the same books...for free.
Secondly, what is the purpose of having 10 books on a machine when you can read just 1 at a time?

Or you can just download them from a torrent site.

I know, I fail to see the point at the moment for the general reader.

There is an obvious answer to your question about "who wants to read 10 books at a time?" What advantage I do see is for students. As a student until recently, it was frustrating when an essential text was out of the library or I needed seven or eight hefty tomes and couldn't/didn't want to sit in the library picking through them (or as an undergraduate needing journal articles but couldn't because only post-grad students could take them out). It would have been essential to be able to download digital copies of papers or even books so that everybody could have access to the same material at the same time.