I just assume all reviews are lying unless I know the reviewer or have validated their past reviews. I don't know why these sites don't lean into the social angle and weight reviews by social-graph distance. This certainly doesn't mean you have to HIDE the public reviews by unknown people.... just give an incentive to give input at what sort of reviews you want.
Doesn't that require the user to curate a friends list of people with comparable tastes? I've never met someone who has my exact (eclectic and multilingual) taste in books.
Besides, I wouldn't even know who to 'friend' or 'follow' on a site like this. What's the point? Chances are I'd just end up in some bubble, which defeats the whole point of reading.
Presumably you'd agree with a review and then follow someone.
I can't say I've ever thought of reading as a way to fight against a "bubble", nor am I sure that being in a "bubble" is inherently a bad thing. I don't think my life is any worse for identifying that I'm not into fantasy smut or steven pinker or self-help neuroticism and in fact my life is better without these authors in it.