ArtReview’s Power 100 – the annual ranking of the most influential people in art, now in its 20th edition – looks at the contingencies and continuities of an artworld that, along with everyone else, is working hard to pull itself back together. Faced with a long list of challenges and preoccupations, how is the artworld faring, and what lessons has it learned along the way? The ArtReview 2021 Power 100 makes its case.