What do you get with KFX? It's hard for me to imagine any goodies I'd rather have than a file that I own and can read at my leisure.
https://kdp.amazon.com/en_US/help/topic/G202087570
The writing is on the wall though - DRM is getting better and the easy to crack formats will probably fade away soon.
The solution isn't technical (ie better cracks), it's legislative. Books are special and most e-books shouldn't be DRM'd. Purchasers of ebooks should have the right to resell, to gift, to bequeath, to trade, and do all the other things that have been part of book culture for the past few hundred years.