due to the sheer size & weight of the said bomb... it is not feasible / practical for warfare. it was designed for a psychological advantage during the cold war.

high yield nuke weapons were developed before because of the lack of accuracy & information on strategtic military targets. in effect, nuke bombs before were desinged as city-killers.

most new nukes are now fitted to ICBMs that is accurate within meters of a said target. these are now pointed towards military targets instead of cities.