It seems to me that all of them can be and actively are gamed.
Googling using the extension site:reddit.com caught on for a reason.
They also seem to have a much broader range of things covered now, so I think the strategy was to go cheaper, faster, wider.
Consumer Reports does independent testing with their established criteria. But it's a paid service and doesn't do user submitted reviews.
Steam gets gamed with review bombs but provides plenty of transparency and data for people to make informed decisions. They identify recent review biases and show spikes in volume. Importantly Steam has a generous refund policy with little friction, so they have a profit incentive to match you to a game you want to keep.
Many small businesses get their viral loop started from glowing reviews from family and friends. That sort of growth hack will never disappear, and the subtle cases will be undetectable. I decline to write such reviews, but others won't.
> We will never have completely trustworthy user reviews.
just reading these to comments helped me figure out how to solve this: since apps have location tracking, for restaurants at least, your reviews should be weighted by how much time you spend close to a restaurant. If you claim to like a restaurant, but you don't eat there much, that means your reviews are not reliable. This unreliability would transfer to reviews of places that are not close to your home/work.
bonus points to combine it with confirmed food expenditures on your credit card/applepay.
It's not that people are making up their restaurant visits.
It's that they are going to the restaurant, they had a good time, but they didn't disclose that they are close to the owner, and maybe they overlooked a few things here and there that an impartial reviewer would note.