In addition to Macros's comment explaining some of the details around what the specific claims of that report are, here is the statement from Cochrane explicitly saying that people have misunderstood the report in claiming it says masks aren't effective (and taking ownership of the fact that this is at least in part because of issues with how clearly the report communicates it's findings.)

https://www.cochrane.org/news/statement-physical-interventions-interrupt-or-reduce-spread-respiratory-viruses-review