The other significant feature added was voice chats. The fact that it's easy to forget or not notice is a strong indicator of how much humanity has adopted text chatting as the primary mode of remote communication.
"Humanity" may be overstating it. In Brazil people very commonly use WhatsApp to send short spoken messages, for instance.
You're right, China too. I should have said asynchronous messaging rather than text messaging. Whether short voice, text, gif, or emoji messages, the synchronous phone call is increasingly secondary.
but reason in china is overcomplicated writing system. now young people have no problem to write in pinyin, but older generation will rather send voice message, since it's the easiest way to communicate, 2nd would be handwriting, my father in law is exactly like this, not sure what kind of keyboard use my MIL, my wife is fully westernized in this aspect using google pinyin with QWERTY (!) keyboard, which is rare even by CN standard when most young people still use T9 keyboard
I hope they add voice-to-text-transcription soon. I hate that feature.