Amazon and Yelp and the like may be better or worse at stemming the tide of fakery, but asking them to be better isn't going to fundamentally help. The whole idea is broken.
If you know how PageRank works, how it was gamed by blackhat SEO's until Google was forced to fix it, and what Google did to fix it, then you already know how to fix product reviews. You just need to recognize that reviews are links, in the sense that a link counts as a vote of "authoritativeness." Since we also have negative reviews we can easily implement TrustRank (or an Amazony version of it) and quickly identify bad "domains" (products or vendors).
I think it could be implemented poorly in a weekend or two with full access to the complete set of review and product data.
Currently you have a bevvy of brands for China sourced goods. The brands are obviously made up without much thought. Something like "Scarvast" trekking pole. "Vargus" flashlights, "Zukil" wireless speakers. "Brikor" dehumidifiers.
And often times the same seller will have multiple "brands". This is what makes it unreliable and untrustworthy. It's like they live A/B test products on AMZ.
A trusted source of reviews has proved itself successful with the USB-C cable example and Benson from Google verifying all of them
Often they are just Chinese-speaking American entrepreneurs. The problem is the lack of IP protection in China. And lack of any interest in branding and brand differentiation, hence you got "brands" that sounds like they were picked via /dev/rand. And of course everything is probably manufactured in the same 3 or 4 factories.
Lev Andropov: It's stuck, yes?
Watts: Back off! You don't know the components!
Lev Andropov: [annoyed] Components. American components, Russian Components, ALL MADE IN TAIWAN!!!