Still I think ebooks are a different product. At least in my head. I have a different emotional relationship with a physical book. The information within isn't in competition with the endless a "wealth" of information available legally or not.
For text books piracy is a victimless "crime" in my case, as having a digital copy or not, is independent from financial loss above a certain price tag. That is, I can't afford most text books, so I won't buy them; piracy does not influence the income of the publisher. On the other hand, if I really need/want to buy a book, I am likely gonna get much more intimate with it. Let's face it, digital copies are much more likely not to be read. Maybe only indexed and searched as part of a collection. Digital has a different value. (Although, I ofc understand the superficial dilemma here.)
This is the situation we got IMO.
Side note: You, as someone from the industry, I assume we can both agree that at the very least, a free digital copy should be included with every physical one, right? That just silly and artificial to separate, if you make an argument for the value of content and presentation.
A hardcover will cost around $3-$4 in printing costs. Even still, ebooks can be a good deal. To use a recent example that wouldn't yet have any digital discounts, there's the John Boehner book [0]. As of this comment, it has an MSRP of $29.99. The Kindle version is $14.99. At actual retail, Barnes & Noble charges $23.99. At Amazon it's $17.99, which makes the savings on print costs a wash.
Mid-size paper backs are usually a fair bit cheaper too. Mass-market editions are the bad deals: In print they retail around $8 to $10, which is usually the ebook cost too. However, many books never make it to mass market editions theses days.
The bulk of the costs involved in bringing a book to market are the people: Time to review the "slush pile", pay the author, editor, copy editor, typesetting, marketing. And many books either lose money for the publisher or barely earn out the author's advance. Mid-list authors who can consistently earn out their advance with a healthy margin are the ones that keep the lights on long enough for the publisher to (hopefully) catch lightning in a bottle with a block buster, or at least an outsized success.
Of course all of the costs above assume you're buying a new copy. Used books are often a very good deal.
[0] https://www.amazon.com/House-John-Boehner/dp/1250238447/ref=...