Pandemics need high population densities to start, so it is very likely to have the origin in a large city. Even if a virus did emerge in a smaller city, it would probably fizzle out without raising alarm and being detected. At the same time, large cities in industrialized countries usually have at least one virology lab. I could easily find one in each of the top-10 most populous Chinese cities (which includes Wuhan). SARS is relatively new and hit China pretty hard, so it is also not surprising to have a lot of research in the country. Overall, it would probably be more surprising not to have a SARS research group close to the origin of a pandemic.
Pandemics need high population densities to start, so it is very likely to have the origin in a large city. Even if a virus did emerge in a smaller city, it would probably fizzle out without raising alarm and being detected. At the same time, large cities in industrialized countries usually have at least one virology lab. I could easily find one in each of the top-10 most populous Chinese cities (which includes Wuhan). SARS is relatively new and hit China pretty hard, so it is also not surprising to have a lot of research in the country. Overall, it would probably be more surprising not to have a SARS research group close to the origin of a pandemic.
The lab worker story is bunk. According to the institute itself, no COVID antibodies were found in a serology study of the workers (see page 119 in https://www.who.int/docs/default-source/coronaviruse/final-j...).