Chess and tennis rating systems work reasonably well. Academic grading does not. Academics will never change; the humanities will never go along.
While sites like Netflix use all the AI they can muster to tune and individualize their recommendation systems, the review systems we know best rely on straight democratic votes that can be gamed. Or worse, they rig the votes for profit.
The AI objective function should be to synthesize advice relevant to each user. As a component of this, treat each reviewer as a tennis tournament, to develop a tennis rating system summarizing reviews? One could apply weights tuned to each user for the relevance of each other user's reviews. If there was a shadow economy behind these uses, as if a hedge fund had to pay pennies to include each voter, the "review bomb" voter's inputs would quickly become useless, and be disregarded.
What we have instead is singularly dumb. Is there room for a startup here? Google page rank was obvious in hindsight. Won't this too be obvious in hindsight?