The B-1 was designed for a role (low altitude nape of the earth bombing) that was obsolete before they worked out the bugs in the jet (Russian interceptor and fighter aircraft got look-down shoot-down capability). The B-1 was kept alive because of its electronic warfare capabilities, but efficiency of the bomb trucks matter more than high-speed delivery in a hostile radar environment these days.
The B-1 was designed for a role (low altitude nape of the earth bombing) that was obsolete before they worked out the bugs in the jet (Russian interceptor and fighter aircraft got look-down shoot-down capability). The B-1 was kept alive because of its electronic warfare capabilities, but efficiency of the bomb trucks matter more than high-speed delivery in a hostile radar environment these days.