Well, with some e-readers, but not the Kindle, you can check books out from the library or get the out-of-copyright ones on the Web for FREE. Project Gutenberg and the Adalie University Electronic text Collection are both great resources for the old stuff. My local library has well over 10,000 recent ebooks to lend.
Real e-readers do not have backlighting so they are just like reading paper, not a computer screen. I enjoy mine.
There are some drawbacks. They are not really simple to use. They do not have color.
I still buy and read paper books. The books I treasure, I’ll want to have on the shelf and experience the smell, touch, etc. For light reading (Tarzan, Allan Quatermain, Doctor Who) the ereader devices work just fine.