Why is Apple not using it?
It's a free standard and actually a good one. What is their reason not to use this?
Google has backtracked on its decision not to implement Pointer Events in the Blink web browser engine used by its Chrome browser. Pointer Events is a W3C recommendation that makes it easier to support touch and pen control, as well as mouse input. The specification was originated by Microsoft to improve Internet Explorer (IE …
"Honeybadger don't care"
Apple do their own thing. They don't care about anyone else unless there's a potential P&L impact. Think 1990's Microsoft.
Also, step into their shoes; what if you have already invested time and effort on your own solution and you're pretty happy that it works; why would you chuck that in the bin just to "play nice" with your competitors? Apple don't play nice.