Yeah, that was very obvious. We're in the Yonko Saga, which is aimed towards finding Laugh Tale. That's bound to be resolved first. The World Gov. also has too many developing plot lines to suddenly be wrapped up. Fujitora's reformations, the Science Division, the Gorosei and Alabasta... Imu—sama... Hell, Oda invented an entire faction solely to oppose the World Gov.
They ain't going down til EoS.