Have you read the ten-year retrospective on the ebook revolution that Vox published a few weeks back? Go read it, and then come back here so I can point out what they missed.
The thing about that piece is that it said that the ebook revolution didn't happen, which both is and isn't true.
Vox reached this conclusion based on a glaring but quite common error: They looked at industry-wide stats, and drew conclusions based on the assumption that any change would affect all parts of the book publishing industry equally. This was a mistake first because the industry is not a homogeneous whole, and also because focusing on sales stats keeps you from seeing the more radical changes.
The thing is, ebooks did revolutionize parts of the industry: Non-fiction in particular has been changed radically, but you might not be able to see that from sales stats.
For example, textbook sales are not going digital so much as they are being nibbled away by OER (open educational resources). This is the name for curricula that can be downloaded for free, edited, remixed, and shared.
OER has revolutionized and continues to revolutionize education, so much so that textbook publishers are pursuing ways to force students and schools to license their textbooks (another change you will not see reflected in simple sales stats).
And that's not the only category of non-fiction that has changed radically over the past ten years.
One of the major oversights of the Vox piece was that they missed how the internet is killing non-fiction. People aren't buying books to learn new things any more; instead they get their info from Youtube, on how-to sites, and direct from experts in online forums. (One common refrain I hear is that there is no Kindle for non-fiction, but there is: it's your web browser. )
And consumers are also getting content via subscription access rather than buying one ebook at a time. Remember what O'Reilly said when they shut down their ebookstore in 2017?
They stopped selling ebooks because they earned more by making the ebooks available through Safari, the subscription service that O'Reilly launched in partnership with Pearson in 2000. (O'Reilly bought out Pearson's stake in 2014.)
Speaking of subscription, let's not forget Kindle Unlimited, which pays out over $240 million a year. We do not know how much revenue it is generating for Amazon, but its royalty payments make it one of the top five ebookstores all by itself.
That money is mostly going to indie authors, who have stepped into the void left by the Big Five when those publishers decided to kill their ebook sales with agency pricing.
Indie authors dominate a number of genres, including SF, thriller, romance, and fantasy. You won't be able to see it from the industry-wide revenue stats, but these four genres went primarily digital as far back as 2015. While I do not have current stats, there is no reason to expect that a reversal of the trends that lead to a digital majority in those genres.
And that, folks, is where the revolution happened.
P.S. When I started working on this post, I was reminded of something that William Gibson said back in the 1990s
“The future is already here – it's just not evenly distributed".
That is certainly an accurate description of the impact of ebooks.