The point of the lab-leak hypothesis is not to find the exact historical truth of what actually happened. We probably can never find out for sure, and for political reasons it would be difficult to pin it on one culprit.
The question is only: Could it have happened this way? Is it plausible? If so, then we need to increase our security measures.
I think it is very plausible. There have been SARS lab leaks before, there were local attempts at cover up, and so on. There is no evidence for a lab leak, but it could have happened, and that is enough.
How do we tighten the security measures? One way would be to ban gain of function research. I'm not an expert, so if you say we need this research, we have to find a way to do it more safely. Maybe we can perform the research with 100% transparency. Complete surveillance of the lab, only joint multi-national labs allowed, frequent external audits, intense medical observation of the researchers, .... I'm sure experts can come up with useful precautions. The thing is there are likely precautions that were possible but considered too cumbersome or expensive. But in the light of a global pandemic and the plausibility that it may have been a lab leak, it is time to reevaluate the cost-benefit analysis.
(And of course, the zoonosis hypothesis is also plausible, and we have to do something about it... and think about deforestation, urban growth, wet markets, and so on.)
The whole reason they were working with chimeras is that attempts to culture the virus for gain of function research failed. Using the unproven lab leak origin theory to put a stop to research that wasn't actually being done is not reasonable or logical.
That is a really uncharitable reading of what I said. I don't know the details of what they were researching, I am not an expert. I'm just saying, the scenario that it could have been a lab leak, or that there could be a lab leak in future, should be taken more seriously. I don't know if they did GOF experiments (and I'm sure the pop-sci image of monkeys in cages a few feet apart is probably wrong). But we should think of regulating more strictly whatever they did (or didn't) do that could cause such an outbreak.
There are multiple different biosafety levels for labs. All else being equal, a leak is more likely from a BSL-2 facility than a BSL-4 facility. Perhaps all such research should be limited to BSL-4?
The question is only: Could it have happened this way? Is it plausible? If so, then we need to increase our security measures.
I think it is very plausible. There have been SARS lab leaks before, there were local attempts at cover up, and so on. There is no evidence for a lab leak, but it could have happened, and that is enough.
How do we tighten the security measures? One way would be to ban gain of function research. I'm not an expert, so if you say we need this research, we have to find a way to do it more safely. Maybe we can perform the research with 100% transparency. Complete surveillance of the lab, only joint multi-national labs allowed, frequent external audits, intense medical observation of the researchers, .... I'm sure experts can come up with useful precautions. The thing is there are likely precautions that were possible but considered too cumbersome or expensive. But in the light of a global pandemic and the plausibility that it may have been a lab leak, it is time to reevaluate the cost-benefit analysis.
(And of course, the zoonosis hypothesis is also plausible, and we have to do something about it... and think about deforestation, urban growth, wet markets, and so on.)