Or is he viewbotting? How big is OW in China really?
Chinese streams tend to have massive viewer numbers. Part of it could be population (remember China has over 1 billion people all on the same timezone), while part of it could be inflated numbers. Viewership stats for Chinese streams are generally considered unreliable because they have a reputation for being inflated (this wouldn't be Leave's doing, but the streaming service itself).
However, I'd say Overwatch looks fairly popular in China from an outsider's perspective. They are the only region that regularly has tournaments outside of Contenders and most of them end in LANs. Someone more familiar with the Chinese scene can probably speak with a more informed perspective, though.
I think that's the part, what most people forget about China and their 1,4 billion population, where Europe (includes Russia etc) is 741 million (European Union 512 million) and North America 580 million (USA 330 million). I think most of the "western world" (depends, which countries you count in as "western") doesn't have more than 1-1,5 billion people, which is about same than China.
I've discussed this somewhere else actually and that number there doesn't exactly mean the number of viewers watching
If you go to the site and hover over that number you can see that it doesn't actually translate to views, it translates to popularity rating
Which, while scales with views, doesn't exactly equal to number of viewers watching
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