What systematic reviews are NOT are literature reviews. They avoid cherry picking individual studies – consciously or not – that fit a preconceived idea or narrative. This attempt at comprehensiveness is important for policy: where research summaries on issues of national importance should avoid bias towards some studies and the exclusion of inconvenient research.
— Read on blogs.lse.ac.uk/impactofsocialsciences/2022/04/27/quick-but-not-dirty-can-rapid-evidence-reviews-reliably-inform-policy/