I remember the early days of the ipad 1 where publishers and technologists were stoked about all the cool new interactive things they could do with this format.

It flopped. It turns out interactive infographics and scrollytelling are fun (and costly) to make but readers don't really like them.

The smashing success story wasn't actually what you can do with the new devices' screen, it was audio. It turns out audiobooks (and podcasts) are a huge hit when the price is right and you make it accessible enough.