Those numbers are for the case where you want all possible pairs of two vectors to have a corresponding query that returns those vectors as the top two results.

If you mostly just want to find a particular single vector if possible and don't care so much what the second-best result is, you can get away with much smaller embeddings.

And if you do want to cover all possible pairs, 6500 dimensions or so should be enough. (Their empirical results roughly fit a cubic polynomial.)