[They dont because they are unable to support a battle group that far from their own shores.]
The Bering Sea is a closer reach for them than Hawaii, or the US mainland.
Hainan to Hawaii is over 6,000 miles and not a friendly port in between.
Putting 3 Frigates in waters 2,500 miles from home with a friendly port 500 miles away is something the Iranian Navy could do. Yet the Chinese brag about it.
Just like they brag about all the very cool, anime-looking weapons they’re working on...as if they are widely deployed.
While still not being able to manufacture a high-performance jet engine that will run for more than 100 hours. Even when provided the detailed engineering plans.