The thing is that trust with Amazon is just not about the product reviews.
I have been genuinely amazed by Amazon service, delivery and choice but those days are over.
Years ago some right on woman ticked me off for recommending her a book that you could just get on Amazon. At the time I thought her attitude was a bit extreme - essentially she was already of the boycott Amazon persuasion. At the time I could not care less for bookshops, that battle had been lost and Amazon gave choice, delivery and price that couldn't be argued with.
Years later I have almost came to this woman's conclusion. What has changed? There are lots of small trust things. It seems that Amazon will gladly tender and take on the most odious work for the spy agencies that the rest of Silicon Valley would not touch with a bargepole. It doesn't appear that Amazon want to pay any taxes, which is all very clever but I would prefer to see a society where businesses pay taxes and individuals don't. But, despite these problems, I will still want Amazon stuff.
Now if the reviews are not trustworthy and I can't trust them to have the best prices then that is it really, I stop being a customer of Amazon and, a decade after crazy woman scorned me for buying from Amazon, I become of the opinion that she was right all along with all her talk of 'illegal monopoly' and 'tax avoidance'.
Trust is a fragile belief-y thing and when it has gone it has gone.