Some anecdotes:
I (late 40s) love my eink ereader (a Kobo Aura HD) when reading for pleasure. I also use it for reading a lot of web-page articles away from the computer (via it’s pocket integration). I’ve read 205 books in the last three years[1] and I would say less than five were physical books.
On the other hand, almost all those books were fiction, read for pleasure. I would never read that amount on a tablet screen or any similar screen that emits its own light.
I also find for technical topics, especially if they involve lots of diagrams or tables, I prefer physical over electronic because the ability to navigate around and annotate is so much faster and superior.
§
My kids, who are now in the teens and both avid readers, prefer physical books over electronic almost exclusively. They are willing to wait weeks to get hold of a physical version of an eagerly anticipated tome rather than get the electronic version immediately.
The only time my daughter uses an eink reader is when something she really wants to read is only being published electronically, never physically. I have tried to get her interested in a few books or series I think she would like, but with the rare exception was unsuccessful unless I could provide a physical version of the book.
§
At the opposite end, my dad (late 70s) who while not quite a luddite is far from a digital native, has expressed interest in getting an ebook reader primarily because he can then change the text to a comfortable size for his failing eyesight.
[1] http://www.michevan.id.au/tag/books/