Note also the time factor! The emotional binding of social media and communication on satisfying feeling and actions needs time which is lost for important other work, for instance research.
Yes, sure, the kind of research products you are delivering are quite different from research papers or more traditional research products, so the impact it has on productivity is that it diversifies your research output. This implies that social media use is not useless, though more risky. You are not sure that the kind of work you do on social media will be ever recognized and valued such as publishing on high impact journals.