Certainly there are bad cables, and sparkles are clear signal dropouts.

The description of that cable though, says Perfect-Surface Technology applied to extreme-purity silver provides unprecedented clarity and dynamic contrast.

An HDMI cable can not affect the "clarity" or contrast of the image or audio it carries. It can just succeed or fail (and failure results in obvious pixel noise, not some overall lowering of contrast or clarity like in analog)

All cables have some probabilistic failure of corruption, it isn't binary. It's the same as what going from 5 9s in your application to 7 9s, which involves a huge cost with distributed databases multiple data centers etc. etc... For most people it's a waste, but if you really value not having the occasional white speck, it could be worth a better cable, which may cost a lot more to recover design costs of making a cable very few will want to buy.

I don't know this world. But could it be because the HDMI protocol doesn't require correcting all errors? And newer cables produced fewer corrupt packets which might have resulted in "sparkle"?

Different HDMI cables have different bandwidth which is a result of their physical construction, same way as you have different bandwidth ethernet cables. Sending signal on the edge of cable's capability may be causing intermittent problems.