This is an extremely mainland-centric view. Cangjie is the dominant IME in Hong Kong.

That's why I said almost all

It’s only almost all if you only interact with the millennials or younger. Pinyin is an IME for Mandarin. If you aren’t fluent in Mandarin, chances are you use voice input or stroke typing.

Why shouldn't it be mainland-centric? Mainland China is 99.5 percent of the population of China. That's like refuting a claim about Americans by calling it "a very non-Pennsylvanian view".

Because China is not the only place where Chinese languages are spoken. There’s more than 10 million ethnic Chinese in Southeast Asia alone. And it’s not only a mainland-centric view: it’s a mainland–Mandarin speaking centric view.

Pinyin is used as input to select characters, but the final text that's used to communicate is composed of characters.