8 years later, the physical book is still in widespread use

Industry Sales Dipped 1.4% in First Half of 2018.  (Publishers Weekly, 9/7/2018)

For ebooks, a slightly smaller slice of the revenue pie.  Sales of e-books, meanwhile, fell again; they dropped 4.5% and accounted for 20% of adult book sales in the first six months of 2018. In the comparable period in 2017, the format generated 21.8% of revenue. 

Reported in Nicholas Negroponte: The Physical Book Is Dead In 5 Years.  (TechCrunch, 8/5/2010)

Related reading:
The revival of vinyl records.  (Forbes)