Handwriting is widely used by 50+ yo people in China. The pinyin system was not taught when they were young.

I can confirm. My girlfriends father needed a new phone and he needed a phone with character recognition.

I dont recall seeing any of my friends or colleagues here using this feature.

I write on my iPhone and use pinyin on my Linux, Mac and Windows computers. I'd like to write Cantonese and Japanese too, but I don't do that enough to bother finding the relevant input software. Using a hiragana table is much slower for me than writing the characters using my index finger.

It is useful when you are trying to type a character that you cannot quite pronounce/pronounce erroneously. It happens quite often even with Chinese people. With this input you can simply imitate the strokes.

That's definitely true. But for average day-to-day text input, people seem to vastly prefer the "hopelessly slow" pinyin method.