The last bothers me. It sounds like you invalidate his/her comment because you don't use it. WeChat is definitely more Chinese-speaking population dominant, but not necessarily just users in China. This is a massive network.
No, I'm using me as an example, the point being that the Chinese market is a bubble at least when speaking of Internet services.
What this means, for one, is that there is no cooperation or interoperability and these policies of the Chinese government are to blame.
From the sources available online WeChat's userbase is 90% Chinese. [1] So it might be a massive userbase, but it's not diverse.
Ask yourself this: would WeChat be successful if it weren't for the Chinese government favoring it, even going so far as to ban alternatives or worse?
Maybe, but maybe not, we'll never know, but products like WeChat are definitely not the result of free market competition in an international context.
If you know my phone number, you can contact me on WhatsApp. But you can't contact me on WeChat, because I'm not using WeChat, because I'm not living in China to be forced to use it and so the opportunity for a Chinese to contact me isn't there and I'm not going to install WeChat just because I might get contacted by a Chinese (there's always email).
Of course, in the future I myself would likely be interested in doing business in China, so I might end up wanting to talk with WeChat users.
But seeing such developments by the Chinese government is to me a strong signal that China is not a good place to do business. It might be for huge companies like Apple which have infinite resources, but as a small guy I couldn't bring myself at the moment to phantom developing a product, or delivering services to the Chinese market given that it's definitely not a free market.
So no matter how you look at it, the Chinese government has been maintaining an information bubble, keeping such products as WeChat tied to the Chinese market.
