They have been saying land war fighting is obsolete for the last 60 years and the wars since then have always devolved to boots on the ground, sand, swamp....
Wars have only devolved to "boots on the ground" because we don't fight real wars anymore -- we only take sides in civil conflicts. That may sound flippant and cavalier, but almost every U.S. military engagement since World War II has fit this description -- including some you don't hear much about (like the joint U.S.-British operation in 1953 to topple the Mossadegh government in Iran).