"But wait!", you say, "there are some legit reviewers out there." Yes, there sure are, by my starement is accurate, because for every legit review site with aws referrals, there are tens of thousands of ml created spam referral sites.
And so the real review sites are often lost in the mix regardless, which makss arguments to keep those results pointless.
But google leaves them there, and this is the same sort of site which, if it were an email, would immediately end up in a spam folder.
And beyond this, the other part of the problem is their ridiculous aliasing of search terms, which helps spammy sites come back as a response.
You say google lost? It's not losing, if you just don't care.
Frankly, it's just a return on investment thing. As long as only a few people per tens of thousands bolt, why spend the r&d?