His opening is that it “turns out… these masks are completely useless”. That’s absolutely not what the meta analysis said. This article by The Economist gives a breakdown.

Let’s start with one of the people from Cochrane itself:

“The number of deaths would have been much higher” without “mask mandates [and] social distancing”, Michael Brown, a member of Cochrane’s editorial board, said later. “I’m very confident of that statement.”

The big problem about Cochrane’s approach is that they only consider randomized control trials. That’s fine for something like a drug where only the person taking it is affected. But masking is a public health intervention done on a population level. If masked people are just sent out to live their lives, they are in danger from unmasked people around them.

The best study came from Bangladesh. Some villages were provided masks, instructions, and incentives for wearing them. Others weren’t. At the end, they did antibody tests. Antibody levels and symptom reports were 10% lower in villages without masks. This was despite a less than perfect track record on compliance.