A number of authors have written about this and the tldr is that ebooks aren't really any cheaper to produce.
Paper is cheap. Shipping is cheap. The incremental cost of making a physical book is so small as to be noise in the overall book price.
When you consider that different ebooks and different font selection can result in lines and pages breaking at any random place, ebooks may actually be more expensive to produce.
If that is true, of which I remain highly skeptical, then it implies that books are wildly inefficient to produce.
What on earth are all the middlemen between book being authored and it being sold to a customer that add so much overhead that the cost of printing and logistics disappears in the noise???