I think there is a set of problems to solve first before you can "solve reviews".

The first and biggest one (in my opinion) is global unique item identifiers for the products. This reduces the sheer ridiculous volume of reviews you have to contend with. The other problem this solves is that the "review" is now reasonably guaranteed to be attached to a product and not "seller plus product". This leaves very little wiggle room and incentive for dollar-store / drop-shipper / chinese knockoff sellers to fake reviews.