I think this brings up a philosophical issue that is worthy of more discussion. If somebody listens to music through a $10 speaker cable then swaps it with a $10,000 speaker cable and suddenly claims it sounds better, are they really wrong? We know the science is clear that the signal reaching their speakers is identical enough that no biological organism can hear a difference. But if the cognitive bias of knowing it's more expensive and seeing that it's prettier makes them enjoy the music better than the $10 cable, then to what degree is that actually "bad"? The constant sight of the prettier cable has rewired their brain to some degree to make them like their music better!
The bit where you say "we know" is not at all known to a lot of the people, and they actually do think the cable truly is changing the sound waves in audible ways.
That is why so many audiophiles dispute DBT outcomes so denialistically, claiming DBT are prone to artificial null outcomes, or they induce stress in participants which impedes their ability to discern audible changes, or they engage the analytical left brain whereas music appreciation is more right-brained and hence certain perceptions can't be accessed during DBT, or....you name it.
I have repeatedly supported your suggestion that it is no bad thing to purchase gear that just happens to turn on your non-sonic filters/biases and create a superior
impression for oneself.
BUT if people truly believed that it was all in their head, then they wouldn't come onto every audio discussion or review space and attribute the superior qualities to
the gear itself, would they? But that is exactly what they do.