Yep, all dacs sound the same, all cables sound the same, all amps sound the same, all preamps sound the same, usb is the best interface, on and on with all the audio myths.
Huge difference in sq, huge difference in chips/non-chip dacs (I only get fpga based dacs), and usb is the worst interface to a dac. If it was so good, why the hundreds of reclockers, cable splitting the power/data runs, femto clocks, offramp devices, on and on. The better streamers/dacs don’t even have usb, my streamer doesn’t.
Remember the special interfaces between cd/sacd players and their preamps? Look at Esoteric products, they use i2s.
99% of audio people will never try/audition i2s or Ethernet interfaces because the cheaper dacs don’t include them. So before anybody has an opinion on i2s or Ethernet, verify that they has actually used this or disqualify it right away.
My dac includes all interfaces and I have tested usb vs Ethernet vs i2s. Last place is usb, second place is Ethernet and 1st place is i2s.