Authors hit by bad reviews on Goodreads before review copies are even circulated

This kind of exposes how valuable reviews actually are -- likely not very. People like reviews, but some person you don't know using some unknown set of criteria to evaluate a product turns out to not actually offer any value. Taking the mean of this data ("4.5 stars on Goodreads!") also doesn't improve the quality of the data.

I'd disagree. Real, honest reviews are genuinely useful to me as a consumer particularly if the review outlines what type of person the reviewer is, too.

That is the whole point of the review scams - often I'm not an expert and I know it. I need some widget, and there are 10 choices. I want someone independent to review all 10 choices and tell me which is best so I don't waste my money buying a bad one. Lacking someone with the money and time to buy all 10, at least seeing the reviews of someone who has one is a suggestion on if that one is really as good as they say. Though if someone only has one they tend to review it well because nobody wants to admit they bought something that wasn't the best.

If the reviewer is consumer reports they for years were this independent reviews. (I've heard accusations they are no longer as independent - make your own decisions) They often don't know enough about the product to understand why long term the more expensive one might be better as opposed to just overpriced, so not perfect, but still better than buying everything yourself.

in germany there is stiftung warentest: https://en.wikipedia.org/wiki/Stiftung_Warentest

they have been doing this for decades. they fund themselves by selling a print magazine and paid online access. their reputation is so good that products that get good test results often use the result in their ads or print it on their packaging.