B-2 is getting old, and we only have 20 of the things and other than maybe a special niche mission or two it's reserved almost exclusively as one of the USAF's two legs of the nuclear triad (the idea that our strategic nuclear capability is "stool-like" and needs three legs to be stable at all is one of the great marketing triumphs of the legendary old-school air-power advocates )

The exact requirements for this capability have been debated for years, running the gamut from supersonic, manned, unmanned, optionally manned, conventional to nuclear, stealth to not. Guess they settled on something similar to the B-2. Could be useful as conventional deep-striker if you own enough of them to actually risk losing one in combat.

Worth noting that the flying wing format has better inherent stealth characteristics than the stealth fighters, which need control structures sticking out. A smooth flying wing should be immune to the VHF radar (the latest anti-stealth bogey-man).