It's not hard at all, it just needs moderation. Amazon is absolutely the bad actor because they allow sellers to edit their listings to utterly unrelated items, rather than having moderators reject those changes. It's not hard to prevent a cheap kitchen utensil with 2,000 positive reviews from being edited into an expensive drone.

And while moderating things like social media at scale has a lot of challenges, moderating product pages does not. There are orders of magnitude less of them, and they don't need to change that often.