It is not as cut and dry as you think. Also it is rather hard to get any evidence when you aren't allow to visit the "scene of the crime" so to speak and all data is being withheld.

https://www.nytimes.com/interactive/2024/06/03/opinion/covid...

Even Dr Fauci said in 2021 he was "not convinced" the virus originated naturally. That was a shift from a year earlier, when he thought it most likely Covid had spread from animals to humans.

https://www.deseret.com/coronavirus/2021/5/24/22451233/coron...

(..February 2023..) The Department of Energy, which oversees a network of 17 U.S. laboratories, concluded with “low confidence” that SARS-CoV-2 most likely arose from a laboratory incident. The Federal Bureau of Investigation said it favored the laboratory theory with “moderate” confidence. Four other agencies, along with a national intelligence panel, still judge that SARS-CoV-2 emerged from natural zoonotic spillover, while two remain undecided.

https://www.nejm.org/doi/full/10.1056/NEJMp2305081

WHO says that "While most available and accessible published scientific evidence supports hypothesis #1, zoonotic transmission from animals, possibly from bats or an intermediate host to humans, SAGO is not currently able to conclude exactly when, where and how SARS-CoV-2 first entered the human population."

However "Without information to fully assess the nature of the work on coronaviruses in Wuhan laboratories, nor information about the conditions under which this work was done, it is not possible for SAGO to assess whether the first human infection(s) may have resulted due to a research related event or breach in laboratory biosafety."

https://www.who.int/news/item/27-06-2025-who-scientific-advi...

WHO paraphrased: We have no data at all about the Wuhan Laboratory so we can not make a conclusion on that hypothesis. Since we have data relating to natural transmission from animals we can say that situation was possible.