there really is more to wire than gauge
Speaker cable is a bit different from a lot of the interconnect cables we handle, in several respects. Because speakers are driven at low impedance (typically 4 or 8 ohms) and high current, speaker cables are, for all practical purposes, immune from interference from EMI or RFI, so shielding isn’t required. The low impedance of the circuit, meanwhile, makes capacitance, which can be an issue in high-impedance line or microphone-level connections practically irrelevant. The biggest issue in speaker cables, from the point of view of sound quality, is simply conductivity; the lower the resistance of the cable, the lower the contribution of the speaker cable’s resistance to the damping factor, and the flatter the frequency response will be. While one can spend thousands of dollars on exotic speaker cable, in the end analysis, it’s the sheer conductivity of the cable, and (barring a really odd design, which may introduce various undesirable effects) little else that matters. The answer to keeping conductivity high is simple: the larger the wire, the lower the resistance, and the higher the conductivity. -- Blue Jeans Cable
That’s all there is to know about wire. No magic, no sentient being.
Frequency response is not paramount
If not paramount, I can’t think of any other thing that is more important. The entire freq spectrum of the music must be reproduced.
Signal to noise unless obnoxiously bad isn’t even relevant
Would you buy an amp with 15% THD? Regardless of what you hear, it’s an indication of the skill of the amp designer.
Watts aren’t equal and hardly even matter
The watt is the unit of measurement of electrical power. Period. Manufacturers have been known to lie about watts.
the final arbiter of fidelity is the listener.
The listener is the final arbiter of the decision to buy or not. Fidelity can be measured. Fidelity being identified as the degree to which the signal is faithful to the original signal. Once into your speaker and out into your room, well, that’s unknowable except to the listener.
Cheers