Indeed, but the raison d'etre for a JH-XX would be to conduct strikes at distances within the second island chain as a regional bomber, not only within the first island chain, which as you describe, can be conducted by a number of other assets.
If you want to hit a target (especially a moving maritime one) 2000-2500km away, relatively reliably, with somewhat time sensitivity, a stealthy, supersonic regional bomber is your best bet.
Realistically, there are no land targets which are 2000-2500km away.
Guam is too far away
And the possible 2000-2500km targets in Japan and the Philippines would require overflying a large portion of their land mass, which is not realistic for an aircraft without broadband stealth and in the face of fighter opposition
But if we want to talk about maritime targets, you could take a 1900km JASSM-XR ($1.5M) and add $3M to turn it into an LRASM.
Launched from mainland China, that would take you to at least 1500km offshore, again accompanied by fighter cover.
And it would be far more time-sensitive than trying to organise a large coordinated airstrike with JH-XX aircraft.