why do people feel the need to buy expensive cable

That's who shot J.R. is it not?

everyone knows some have the ability to see fine print others cannot. everyone knows some can taste ingredients others can’t detect. some minds solve puzzles faster than others. there are varying levels of skill and ability in all endeavors . if you have an ability I do not possess I will not declare you wrong. eyes, noses, tongues, minds, hands, feet, and hearts come in varying capabilities. why would anyone purport all ears to function identically?

Because the brain can make you see, hear, feel, smell and taste things that do not exist.

Two good points in the last two posts.
Those are the main problems in discussing the subtle audio changes audiophiles discuss.
Sadly both are used to accuse the 'other side' of being wrong...
I don't think there will ever be any agreement. Other than a possible we can agree to disagree.

Except, Elizabeth, the "subtle" (positive) changes that exotic cables may or may not be able to achieve, are reported as "jawdropping," dramatic," "night and day," etc.  If switching out a cable can make those kinds of improvements, you would have had to have been previously using metallic thread.

Additionally, cables shouldn't introduce anything into the music program, they should only eliminate outside interferences.  Anything else you "hear" after switching cables, IMO, is voodoo magic.