Sure, but it's still data for the groups that they sampled. It would be better to have data for truly random samples. But even then, you'd want demographic dat

Sure, but it's still data for the groups that they sampled. It would be better to have data for truly random samples. But even then, you'd want demographic data for each subject. And then you could compare appropriate subsets of the results with this study. With such data, you could explore risk factors, effectiveness of quarantines, and so on.