One use is to have understanding of how viruses work, so that you can accurately predict spread. If we assume that SARS and MERS (both coronaviruses that seem

One use is to have understanding of how viruses work, so that you can accurately predict spread. If we assume that SARS and MERS (both coronaviruses that seem nearly certain _not_ to have been made in labs) required a knowledge of how coronaviruses work, then a lab doing the general kind of work that was done in Wuhan is real. For example, we already knew that the spike protein was critical in reproduction of the covid-19 virus, whereas we might not have known as much about that if we had no virology labs (I'm not an expert in the field, I might be wrong here). But, for any particular line of research, your question is still a valid one. Is this particular research likely to have a payoff worth the (inevitably non-zero) risk? The issue is how (and who) to make that decision.