Alex Berenson was also criticized by the medical establishment and much of the press for his warnings that the Covid MRNA vacines were ineffective and had major side effects, up to and including death. Now, a couple years later, he has generally been proven correct. As the references to researchers quoted by Wikipedia state, it is true that correlation doesn't prove causation. However, it also doesn't disprove causation. I wouldn't immediately discount what Berenson states--he's generally been right on with his reporting. Many former Coloradoans have talked about what they have directly seen there, after legalization, yet the TOTV response has been "where are the reports?" The reports "are" the direct observations by these people. If you want some data, here's a report:
The Legalization of Marijuana in Colorado: The Impact - PMC