Evidence is often contradictory, especially in the social sciences--that is not a terribly damning charge in this case. Additionally, there is evidence that relationship between social media use and anxiety/depression is not just an association, see Meta's own internal research from 2019: https://metasinternalresearch.org/#block-2e15def2e67a803a83e....

"Meta’s own researchers found — in an experiment they believed was better designed than any external study done thus far — that reducing time on their platforms improved mental health and well-being, specifically depression, anxiety, loneliness, and social comparison."