I remember listening to that as a kid and thinking it must be wrong because we still had radio, we even had books everywhere as far as I could see. Of course we still do, but it's not just literary fiction suffering; book sales tend to go down (pandemics excepted) while the numbers being published goes up.
Anecdotally, I followed an interesting ex-MI6 bod on Tiktok (@theenglishspy) who had ~50k followers and admitted, maybe a few months after publishing a book he'd been pushing, that he had sold less than 100 copies. I had my own go [1] at narrative non-fiction for a cause and also didn't manage to break 100 copies.
Perhaps it's a good thing; the market's saturated, while overall demand for books is falling it's because there are more instant, engaging formats that people are seeking to invest in finding stories. If the internet ever goes down, those books will still be there, we'll just have to find a way to order them.