why do people feel the need to buy expensive cable


I have tried expensive cables and one's moderately priced. I would say there were some differences but I can't actually say the expensive cables were better. IMHO I believe a lot of people buy expensive cables because they don't actual trust their ears and are afraid of making a mistake. They figure the expensive cables are better for the fact they cost more. If you have a difference of opinion or share the same thoughts, I would like to hear about it.
taters
Forgive Geoff...when faced with serious questions he answers either with a question or sarcasm.  One thing for sure...he will say something.  No offense; that is just the way he is, bless his heart.
So sayeth the man who never says anything unless it’s some stalking behavior thing.
Don't believe the naysayers, you do need good quality cable. Believe me its not cheap. For really high end systems you might even need to spend up to $10 a metre.
There's nothing wrong with choosing high conductivity or high purity copper cable. No one is saying cheap narrow gauge zip cord in long run lengths is a good thing. Again - common sense. Super or oversized cable may help reduce voltage drop and inductance but it increases capacitance. This has been covered by "professionals" ad nauseum.

https://www.quabbin.com/tech-briefs/why-cable-capacitance-important-electronic-applications

https://www.eeweb.com/tools/wire-inductance

Common sense and remarkably in this case too, science, tells us that moderation is the best  and most suitable approach. Regardless, I challenge anyone with $5000 cables to run both a scientific measurement and double blind test to reliably determine if they can improve system performance over cables that have similar resistance and capacitance per foot costing in the vicinity of $2.50 per foot. You don't see these kinds of examinations published because they would reveal what most scientifically oriented people have known since before "audiophiledum" was an accepted hobby. No one (at least I) is advocating for an extreme point of view. Quality cable components that achieve the desired results don't have to cost more than a good used car. Anyone who thinks they do is not playing with a full deck, IMH (fairly informed) O.