I dont find that very plausible. There aren't really any places on earth with that many people AND that isolated from the rest of us. For it to be common among them for a long time without escape? I'm not buying it, at least at this level of discussion.
Also there is quite a lot of domestic travel within China, and itβs not that hard to connect via 1-2 people to a major Chinese city with international flights.
With how contagious we know COVID-19 to be, there is no way it started in Southern China and then infected a significant amount in Wuhan and only Wuhan first, of all places.
We don't actually know that it was "only Wuhan first". SARS-CoV-2 is believed to have spread worldwide as early as November.
Wuhan is the 9th largest city in China and also more "blue collar" than cities like Beijing or Shanghai, so the odds that the most visible outbreak of all would occur in Wuhan by chance alone aren't as low as you think.
I'm not saying it could have spread "for a long time", I'm saying it spread undetected "for a while" in a region where significant immunity exists, thus causing no significant amounts of suspicious illness.
That is, the actual ground zero of the outbreak would be Southern China, where you would expect an outbreak of a novel coronavirus to occur, not Wuhan.
