Eh, I do think it's a worthwhile article, because it highlights that retailers should be using plain boxes for shipping high value items, and also advises that people open high value items on video, just in case.

How would an independent investigation prove anything further?

Correct. While a chargeback is a last resort, if the consumer is not lying, then Best Buy advertised a GeForce RTX 5080, but instead gave worthless rocks while taking the consumer's money. That is fraud and the consumer is well within his rights to seek a chargeback. Then the credit card company can seek the damages from the retailer, which they will almost certainly pay because they don't want an outside fraud investigation which could find them criminally liable. Of course when it is on them to investigate, they will find for themselves, take the money, and keep the product, and hope the consumer just goes away. A credit card company with its own lawyers will not, so at that point it's just good business sense to refund the money. It puts them at net zero anyway, as opposed to being up $1200. They were never at risk of being down $1200, which isn't that much for a company the size of Best Buy to fight for stealing from a consumer. They'll do it if they can get away with it, but if they can't, they'll cave.

also the rocks weigh way more than a gpu, so the ups or post office would have a record of that

There’s no proof anywhere that this is truthful, and no, pictures don’t lend credence.

What would you accept as proof then? Because to me it sounds like this logic implies nothing can be proven at all, ever.