I'm pretty sure that
you or I can identify some products on Amazon that very likely have paid reviews in under 5 minutes. If we had access to sales data, we could be essentially certain of it.
Type "Bluetooth" into the search bar. Find the product linked below. Does it seem likely that 45,403 people have given a review for a random Bluetooth FM transmitter?
https://www.amazon.com/Nulaxy-Wireless-Bluetooth-Transmitter... (not an affiliate link)
Type in "phone mount". Do people really feel so strongly about their $12 phone mount that 55K+ of them would write a review of that particular phone mount? What's the matter with those apparently higher-quality phone mounts that have only 500 or so reviews? Do the cheaper rando-brand-name pad-printed ones really out-sell and get out-reviewed by a factor of over 100x?
Do 14K people in just over 4 months feel strongly enough about a pack of straws to write a review? https://www.amazon.com/StrawExpert-Reusable-Silicone-Cleanin... (also not affiliate) "Wow, they totally made my drink colder!" "These are amazing, not boring regular straws; I'll be buying more to give as gifts!" "I will DEFINITELY be buying more of these, not only for our house but as gifts because these are great!" "with plastic straws costing so much, I thought I'd give these a try. I bought this set specifically because I needed shorter and longer straws." That's a reviewer who really knows what they need in the straw department and has made a major dent in their budget by buying these! "the pouch is a lifesaver since this purchase came with many straws" I should go look for reviews on hip waders...
It strains credibility to think the company that can deliver speech-recognition can't spot incentivized reviews. If this is a cat and mouse game, the mice are dominating.