Another term for this is integration. It is not just about not switching apps, it is about ingratiating different features (chat&social&payment&voucher) and providing a natural and consistent experience for users in a single app. You don't see that quite often for SV companies.
How innovative is this? I am not sure, but definitely something new and first popularized by Tencent in the era of QQ before 2008.
> b.) uses QR codes (invented by Japan, popularized by Japan)
Not main point of the article, there are plenty of other innovations in the areas of living streaming and drone technology, but unfortunately you missed them.
> c.) pay things on phone (invented by nokia, popularized in europe)
Not sure about how Nokia and Europe did it, but in China you can pay movie tickets, utilities, taxi fees, fines, etc in a single app. Maybe Europe was a pioneer in this and I wasn't aware of that.