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
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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.