Who's to really say? Do cables,
- hinder clarity or add shrillness?
- strengthen base or bloat the lower end?
- add warmth or smear the sound?
- tighten and focus or lessen body?
I think one has to be intimately familiar with one's system and proceed from there. The more resolving the system, the easier to discern how (hopefully) the cables get out of the way of what your'e hearing. One must pay attention and rely on that (often derided) auditory memory one has to ensure that what improves isn't at the expense of other qualities that one enjoys or has finally ironed out.
It's a game (and a gambit) and should be looked at it as such, but in my experience, I want a cable to only subtract the negatives and not add a thing to the mix.
All the best,
Nonoise