PS Audio did not invent/innovate I2S. That has existed all along in the Sony Philips Digital Interface (SPDIF). PS Audio simply chose to walk upstream and access the multiple data streams coming out of the transport before it was combined into a single data stream for the DAC. I2S is the standard protocol, PS Audio chose to use it with their players and DACs.
See Paul McGowan’s explanation:
https://www.psaudio.com/askpaul/what-in-the-world-is-i2s/