We can't know which reviews are truthful. Presumably some are, some aren't. Obviously allowing the business owner to make that determination is dubious.
I can go and buy however many Yelp reviews I need right now, good or bad for as little as $5/review. Dig deeper and you realize Yelp uses the same tactics as the mafia in Italy to extort store owners and use heavy handed tactics.
Reviews are BS anyway, I don't know you therefore why on earth would I listen to your opinion on something?
Maybe knowing a reviewer actually personally would help it further by noting their consistencies or idiosyncrasies or honesty; but it's long winded method. You can glean a ton by following any person, honest/consistent or not, after all it's what's made social media owners so powerful.