Some comments on that article.

1. Considering this is Saidit, I'm surprised you are sharing a Chinese study.

2. This is a literature review, not a direct study. You are likely aware of that, but not everyone is going to actually look at the article.

3. This is the wildest part to me:

However, results from our meta-analysis on RCTs did not provide evidence to support a protective effect of hand hygiene against transmission of laboratory-confirmed influenza. 

I've never heard anyone arguing that we shouldn't be washing our hands. Do all these anti-mask people not wash their hands either? /s

But seriously , this I think really shows the limitations of these kinds of studies. Obviously you can't tell one group they're not allowed to wash their hands for X weeks, as that would be an ethics violation, just as you can't outright infect them with the flu. To achieve statistical signifance, you'd need a larger sample size than is feasible.

Interesting side note is that one could make this statement: this study shows wearing masks is as effective as hand-washing at stopping the flu. 🙃

1. The findings of the individual studies don't quite match. Here's quotes from the first two cited RCTs:

We observed significant reductions in ILI during weeks 4-6 in the mask and hand hygiene group, compared with the control group, ranging from 35% (confidence interval [CI], 9%-53%) to 51% (CI, 13%-73%), after adjusting for vaccination and other covariates.

Face masks and hand hygiene combined may reduce the rate of ILI and confirmed influenza in community settings. These non-pharmaceutical measures should be recommended in crowded settings at the start of an influenza pandemic.

So I think a fair interpretation is that the results range from "masks don't seem to do much, but wear them anyway because they don't hurt" on the one end, to "masks are effective at stopping the flu" on the other, and this article says that statistically (across only a few studies, mind you--that's another surprise here, how few studies have actually been done) it errs toward the former.

So while interesting, I don't think this is quite the bombshell article you wanted it to be.