Value Sonically: ZERO. CAT-3 will do just fine. You almost can't get it so CAT-5 or 5+. CAT 6 is what was 5+. 7 or 8 are marketing BS) 5+ has a specific bonding between pairs to keep their impedance consistent for 10G. Do you need 10G for audio? Ethernet it packet based. Errors are fixed in the IP stack. Magic is not needed.
Value for placebo satisfaction: Very high to some. If you believe, go for it. If it is real to you, great.
Value for the economy: Makes someone else a lot of money and uses up what you should spend on speakers.
Side note: The ONLY cables that are in fact directional are either balanced cables with a isolated shield/cap bypass which can be used as a band aid for ground loop problems, or pure snake oil. Directional? Audio is AC!