Are they saying the cables aren’t better or that they are better, but the average person can’t tell the difference?
yes.
you can’t tell the difference, therefore they aren’t better.
No, it’s an illustration of pure hokum, and where the hell is the FTC when you need them?
Speaker wire only cares about distance. Up to about 50 feet, the diameter or gauge of the wire matters very little and only from a power loss factor. What’s ironic is what most often is seen, are big fat speaker wires and an underpowered amplifier. Contrary to popular belief most speaker failures are from too little (distorted) power, not too much. But anyway if you look inside your stereo, any stereo, there will be little bitty eeny weenie tiny wires that are soldered to the speaker terminals. If you look inside your speakers, you will see little bitty teeny weeny wires soldered to the other end, and, inside the voice coil, hundreds of yards of very fine enamel coated wire.
16 or 18 gauge “lampcord” is just fine, from a sonic/electrical standpoint. Hell, just buy a couple pairs of jumper cables and call it a day. But it’s a marketing thing I suppose. I think $50 or maybe a bit more for honking big cable is OK, because it is robust and the insulation should be of good quality, and have nice heavy duty spade lugs. Anything more than that is too much.
Notice what would really be practical is flat ribbon, which would be placed under carpets but I suspect when somebody kicks out 8 large for speaker wire they want to show it off. Hm.