Amazon reviews were exploited and devalued years ago. I don't mean there aren't genuine reviews; I mean they've been gamed to the point that they don't really matter anymore. Amazon knows this.
True that. It is so bad that once I sent a irrefutable proof of the seller incentivising reviews, Amazon didn’t take any action at all.
Anything coming directly from a customer is probably refutable. For example, the incentives I normally see are on these little cards they include with the product encouraging reviews in exchange for a gift card or something similar. What's to stop a competitor from falsely reporting it using a fake incentive card they created?
Amazon could take your report then actually open the product and see if the incentive card is actually stored with every product. But that's a bigger task than just trusting the proof you sent in.