Do you visit palm readers? Would you make an important life decision based on advice from a tarot card reader?
How about ghosts - do you believe in them?
If you were diagnosed with cancer, would you travel to a third world country for treatment from a witch doctor or faith healer?
Do you believe that it is possible to talk to the dead through a medium? Can you bend a spoon with your mind?
Are aliens visiting Earth?
Is it necessary to perform a human sacrifice to ensure that the sun rises the next day?
Cables seem plausible on a basic level. Dig deeper, ask some hard questions, start measuring things, and cables turn into Bigfoot or any other silly superstition. And those kinds of superstitions that are designed to generate cash, too.
Even worse, take a hard look at the manufacturers who sell them. They don't actually perform any research because they can't. By their own admission, you can't "measure" cables. Neither can you conduct listening tests, according to them. If you assume those to be true, then you cannot "develop" a new cable as there is no way to differentiate them.
Of course, you can take all the measurements and listening tests at face value. Instead of a rational discussion, you're instead labeled a "hater" or told that your ears/equipment aren't any good. Curious, because the people who believe run like frightened children from any kind of listening test.
Also, those who believe (and especially those who sell) deny that they could be experiencing the well-documented effects of placebo and expectation.
There's a lot more to discredit cables, but you should understand that the harder you look, the less evidence there is. No one has ever measured a difference in the audio range. No one has ever passed an unsighted listening test. And neither will ever happen.
Save your money. Buy cheap cables.