That's because Chongqing is the only municipality in China where Meten is legally authorized to apply for foreign employment permits. I know someone working at the labor bureau in Shenzhen, Meten has no license to hire foreigners in that city, just like every other cities where they are beside Chongqing. It's not that difficult to obtain a licence, unless you have no guanxi, and I think Meten has very little since there are regular raids from the police to check them and also since all the other big language mills have licenses in most cities where they have branches.

Who wants to work for Meten anyway? They ask as many hours while paying much less than the other language mills. It's a Chinese company which means Chinese management and Chinese curriculum, or lack there of.