> Amazon now has a very big financial incentive to move beyond whack-a-mole and truly tackle these problems, which requires A) doing at least as good as Fakespot at identifying the bad actors and B) implementing technologies and policies that discourage buying or posting fake reviews.

What incentive? They're still a giant, and while I've seen people here on HN complain about it, I've yet to see people or companies stop ordering via Amazon due to fake reviews.

Aside from their own sales incentives, why should they invest in something that other businesses (such as Fakespot) are already solving? It's R&D costs they can just not spend at all, and if the public pressure against fake reviews starts to boil up, they can probably buy Fakespot for less than it would cost them to develop the functionality on their own.