I think there's an unexplored niche in searching and reading aloud web content, at least on Android.
There's no easy to find app that lets me easily search and play interesting articles , easily. There's also nothing that fits the context of doing something else and wanting a stream of interesting stuff according to a search query.
And recently there were big.leaps in quality if machine speech.
And maybe there's some role to play for hands-free dialogue with the machine.
And because it is a tool for learning , not just enterntainment , you may be able to justify a reasonable monthly subscription - if the app is effective.
I suspect most companies that offer audio books have jobs. In particular they don't pay as well and I can't say anything about what they actually do, but Overdrive is a local company to me and I know from friends that work there that they're definitely hiring.
I’m a developer with a very wide (and doubtless shallow) experience. And I love audio books.
I use Audible a lot but I do rue Amazon’s excessive dominance in this space.