Maybe this means Apple will bring iMessage to Android in a year or two just to mess with Facebook Messenger.
I know a guy that never set up iMessage on his iPhone - when I asked him why he didn't, he just told me he only uses SMS for OTP which he reads from the notification, so it never occured to him to open the Messages app at all.
BTW outside of the US, Whatsapp is (AFAIK) the most popular messenger. At least in the Western world. I don't know about China.
I think Whatsapp and other E2E encrypted chat apps are banned.