This is not a niche, low volume IC. Its smaller brother is used (I should say was used) by DJI in its Lightbridge video transmission system (that you could find in the Phantom 3/4, that sold in the order of millions). And that's only one product I know of, I'm sure there are many other.

I would love to know how much DJI was paying for that chip, especially after they went to the effort or replacing it with an in-house one (no name Chinese startup) in more recent batches.