"Are masks effective" is the completely wrong question, anyway. The question should be "how effective are masks?"
Preferably, "How effective are masks against X under Y circumstance?"
In relation to Covid, I think it's likely masks reduced transmission. But, under normal social environments, did they reduce it by 5% or by 50%? It makes a big policy difference. It seems that studies are coalescing around masks having a 'real but small' effect, but I get it's a hard thing to study.
Preferably, "How effective are masks against X under Y circumstance?"
In relation to Covid, I think it's likely masks reduced transmission. But, under normal social environments, did they reduce it by 5% or by 50%? It makes a big policy difference. It seems that studies are coalescing around masks having a 'real but small' effect, but I get it's a hard thing to study.