I see people make this complaint a lot, that they want to 'own' the things they buy. But you're ignoring all of the other huge benefits you get from non-physical media. Ebooks take up no physical space, cannot be lost or left behind. Can be read by multiple people at the same time if they're sharing a Kindle account. For example, I have four children and they were all working their way through Robert Jordan's Wheel of Time series at the same time. There was no fighting over who had which copy, or where a copy had been left when one of them finished it. I don't have to store 14 large books on a shelf now when they've finished the series, or go looking for them in a few years if I feel like re-reading. And other people have already made comments about search functions, easy text highlighting, bookmarks, etc that ebooks do really well. It's a different experience than buying and reading physical books. I avoid buying physical books whenever possible
It's like you think that once you buy a physical copy of some media, you have an indestructible copy of it that will last you the rest of your life. I have no problem buying books or music or movies from iTunes or Amazon's stores. I've bought multiple copies of the same CD or DVD in the , only to have to get another one when the copy I was using got scratched by kids, pets or mishandling or just plain lost or stolen. I buy digital versions of all of music and movies now, and I don't even care that I don't 'own' the media. To me, the benefits vastly outweigh any perceived drawbacks.
Also, as someone else already noted, many (most?) ebooks from Amazon 'ship' with no DRM, and can be loaded into Calibre and changed to different formats and device fairly easily.