The review concludes that we have evidence that masks are effective, but the set of papers reviewed cannot be used to conclude we know the level of effectiveness enough to make accurate judgements on tradeoffs in many of the kinds of situations where people were asked to wear masks in the pandemic. So we don't know enough yet.

I read a bunch of the criticisms of this paper and criticism of the anti-maskers misrepresentation of what it said, and none of the ones I found suggested that there were missed papers which provide the precision the review didn't find.

The Guardian article is a mixed bag in my opinion. It tries to get around the idea that we really need more research, it confuses a lot of things.

(BTW, I am not an anti masker, I wore a mask, I find people who whine about wearing them to be a bit pathetic most of the time.)