I knew some audio engineers who had different cables (cardas copper, pure silver, some others i can't remember) on identical headphones (Beyerdynamic) and everybody agreed you could hear not insignificant differences that they would describe as sharper transients, tubelike saturation etc. I consider that they were pro "engineers", they designed hardware and software for Avid.

Undoubtedly. Such obvious delusions are commonplace and don't necessarily correlate to one's scientific literacy or electrical engineering skills.

Such audible differences constitute a testable claim. So far, the number of claims that have withstood reasonable test conditions is zero.

Do you subscribe to the AES journal? This explains why 16-bits isn't enough:

http://www.aes.org/tmpFiles/elib/20170226/18046.pdf

Nice 404.

Nobody is arguing that 16 bits is enough during the recording and mixing process. If they are claiming that 16 bits is insufficient for consumer distributed music, they need to go back to remedial science class.