Text-to-speech models are being improved at an incredible rate. I wonder how long it will take until we are able to narrate any book directly inside our Kindle apps. Also, if this text-to-speech thing takes off, will it be as good as the audiobooks done professionally? And if it is, could that actually start eating into audiobook sales?

I don’t see this happening within the next 5 years. This isn't so much about the technology, which is already impressive, but more about the conflicted incentives at play. Amazon runs both Kindle and Audible, so there’s a tricky balance to maintain.