I've long been using proper e-Ink e-readers and, in fact, the last 15 or so paper books I bought a few years ago, still lie on my unread bookshelf. I have four tall bookshelves with the paper books stacked two deep, and realised that if I'd had to add all the e-books I've read over the last few years, I'd have needed about double that space by now (I enjoy rereading my books).
The linked article goes into some of the benefits of real e-Ink readers (but does leave out the cost difference in books without requiring printing and distribution of paper, wind not blowing the pages, near instant access to a new book, popular highlighted passages, dictionary on hand, can audio read to you, and many others), but it did raise a point that I never thought about... That for many experiencing e-books, they are probably using their phones and that is far as they have gone. A small screen, with light shining in your eyes, reflections, and a very short battery life, is really no comparison to a proper e-Ink eReader.
It is true though that e-Readers don't need as much battery life as they have (can make them a bit lighter then), and that specifically the Kindles really need to start supporting ePub natively as a format. But Kobo and others do seem to have got much of this right, so it is worth doing a broader comparison.
See Why I spent $350 on an Amazon Kindle twice, and would do it again
If you think that $350 is too much to spend on an e-reader, I disagree. The Kindle Oasis is worth buying more than once.