Unless you have some set goal to know a certain body of knowledge (as I presume the four above have), reading should be done leisurely -- not a race to read, and half-understand, as many books as possible.
* While I don't think reading will make me successful, I do find the habitual focus/relaxation aspects of reading to be beneficial
* Regarding paper books vs e-readers, as much as I like the idea of carrying a book in my pocket everywhere, I somehow allow myself to get distracted even on a Paperwhite (I'll start browsing the library and/or shopping for other books), and so I've been thinking of going back to regular old paper books
* Decision fatigue! I spend way more time fretting over what to read next than I do reading
Regarding audiobooks, I enjoy "reading" books in that format, but I have wondered lately about the downside of constantly being plugged in; it's a great way to pass the time doing dishes, but I imagine it's also good to give your brain time to sit quietly without input. It's also a struggle to resist the temptation lose myself in escapist fiction all the time; there's a thin line (for me, anyway) between the type of reading that exercises your ability to focus and the type of reading that acts as a palliative.
On second look, it appears the link was changed from a summary of a Harvard Business Review article on Quartz.com to the actual Harvard Business Review article. The summary had lots of survivorship bias, and the HBR version does not. Thought I had lost my mind for a minute there.
There's practically _zero_ of these mega-successful people (Gates, Buffett, Zuckerburg, Musk, etc.) who don't read. Astonishingly, I can't think of a single one. While that doesn't prove causation, it definitely points at it! Do you want to try to be the first successful person who didn't read?
It's not that reading was this one magical trick that caused them to be successful, but rather that reading was a prerequisite. At least, that's my take.
Citation needed, as well as a definition of "don't read".
For example, for several years now I have been reading a lot less books than ever before in my life, almost zero. However, I took several dozens of courses on edX and Coursera and read a lot of documents on the Internet. Just no books, and a lot less newspaper and magazine articles.
The best way to read more books is to make time for it and read books you enjoy.
And after that I was like 'wew. Okay, I enjoyed that and learned a lot and have, but my life isn't THAT much better because of it.' I've definitely traded investing in relationships or other hobbies for it.
So I've since to slowed down to about 27 a year, and have found that's a good pace for me.