The original directional cables, sans mythology, are a real thing. Grounding for cable shielding matters a lot, and is plainly audible in many circumstances. "Directional" cables only ground the shield at one end, preventing ground loops and interference from grounding both ends. This is electronics 101.

An interesting aside on cables... I play electric guitar a lot, which is far more sensitive to cables than hi-fi gear, because guitar pickups are high impedance, low output devices - enough that capacitance can have audio-frequency passive filtering, and grounding is a huge problem. With passive pickups, I can easily hear differences in various cables I own. But some of my guitars have active electronics onboard (EMG pickups or other preamps), and produce a low-impedance signal. I can't hear the difference with those guitars.

When it gets down to it, I use the cables that are most reliable and comfortable to handle. Sound quality doesn't even enter into it, whether or not it's audible.