Its one of those rare areas where it's still crucial to have a trained and thinking human behind it - vocal ticks and pronunciation quirks are part of the charm. I think an AI reading would be sterile and produce an unpleasant uncanny valley response.
I listen to a lot of audiobooks and have definitely sampled some with narrators I found harder to listen to than that.
That said, there’s a sort of droning evenness to the voice that makes me unsure I’d want to listen to an entire book’s worth, and the voice reading Gatsby is way better than the voice reading Alice in Wonderland, which I definitely couldn’t listen through.
Some (presumably) professional human audiobook narrators have that effect on me!
Though, if a child these days got up to half as much as William, the parents would be in jail for neglect and the child would be in care and up to his eyeballs in Ritalin. And that's before we get onto the Famous Five constantly trying to get themselves murdered by smugglers.