Unfortunately, this is a very accurate analogy.
I like listening to audio books and Audible is definitely very convenient, but I am 100% sure that in the not so distant future Amazon will completely destroy the whole publishing ecosystem in US and that will have horrendous effect on the quality of what is being written and on the availability of things to read.
Audible is good, because it's not sustainable. It's good, because it benefits from the infrastructure that would not exist if books were created for audio instead of paper.
If Audible get really popular, it will just become a centralized long-form podcast service. They're already edging that way with "originals".
It's amazing that after seeing this process repeated again and again in the lat couple decades, people still can't predict when it starts to take pace in yet another industry.
Technically, no one stops any book author from hiring a voice actor and then selling the result from their website directly. This doesn't require a middleman. Yet, how many authors do you know that actually do it?