When reviewing, whether critics would admit it or not, there are certain levels of expectations. When a film like Joker or Jojo Rabbit underperform, a beloved character by all critics along with a beloved actor, and Jojo Rabbit who has a BELOVED director, I think people tend to watch these films with sharper eyes. Especially if there considered to be a potential Oscar contender.
For example, do we really think critics went into a film like Ready Or Not (which has a 95%) or do we expect them to critique a dilm like Joker and Jojo Rabbit more? Idk I think a lot of RT scores often have to do with people's preconceived expectations. Maybe thats just my thinking but thats what Ive noticed.