This is what engineers and scientists who study headphones talk about, only audiophiles disagree with this. I think it's worth remembering that these scientists and engineers also had the opportunity to listen to expensive headphones, such as the Hifiman and Stax headphones. If there was something about these headphones that wasn't showing on the frequency response graph and the THD graph, then those scientists and engineers who have been studying headphones for years would probably have noticed.