Actually, you can lend Kindle books. Paying cash is a "freedom" consumers give up willingly in every area of life. Why can't you keep a Kindle book as long as you want? Bit rot?

I might add that consumers also give up the freedom to cut down trees to make paper, wait for physical delivery, have piles of books clutter up the house and periodically haul them away. I think they actually are aware of these.