You don't own the books, you never did.
I'm OK with this. In my opinion, ownership of books is overrated. There are pros and cons to physical ownership just as there are pros and cons to ebooks.
I have teenaged children that read a lot, and ebooks allow them to all read the same book on their phones/tablets at the same time. I've witnessed them argue about who gets to read a new physical book first, and I'm glad to sidestep that entire argument.
With ebooks I don't have to store the book. I can't lose it or leave it on the train I take to work every day. Yes, DRM sucks, but I still prefer ebooks to physical books. I also don't have a problem "buying" movies from iTunes. I then don't have to worry about storing a DVD, or getting a new DVD if the old one gets scratched or otherwise degraded. I don't have to hunt through a DVD binder looking for the movie I want to watch.