> The defacto industry standard for audio ICs is I²S, an I²C-based bus optimised for audio data.

Nit: I²S has nothing to do with I²C.

(Most I²S chips also have an I²C interface since I²S only carries raw audio data, no sideband like volume control or clock configuration. But that's a separate interface and can also be SPI rather than I²C. In fact, SPI is more closely related to I²S than I²C is.)