PRC uses coast guard hulls, there's nothing being denied, these are generally framed as domestic maritime policing actions for PRC. Which is what makes the comparison generally stupid because PH / PCA ruling is not formal international law. UN/UNCLOS/ITLOS/ICJ has not recognized it, and PRC isn't party to optional arbituation clause, so ruling can't even apply to PRC. Ultimately PRC is simply doing domestic law enforcement in disputed maritime area with is not out of line with her UNCLOS obligations, i.e. until maritime delimitation formally settled at UNCLOS, there's nothing illegal about coastguard doing coastguard stuff in disputed area. This is not to mention up until a few years ago PRC ramming = while many other claimaints where flat out shooting. Like PRC coast guard ships were the last to get armed, some other claimaints already had heavy machine guns of lol missiles.

The flip side of this is US isn't signatory to UNCLOS so they can murder whoever they want on the highseas, and in the Hague I guess.