Always been a pet peeve of mine regarding high end audio. Lots of discussion about hearing a “difference”. Many thousands are spent to hear a difference without regard to whether the “difference” is also an improvement.
Changing the sound of a system is easy. Improving it isn’t. Mostly because it’s an eye-of-the-beholder kind of thing. No other pair of ears can make that determination but you. Add In confirmation bias and the challenge grows from there.