It seems to me to allow the aircraft to make very abrupt pitch changes without actually changing the direction of flight, presenting the belly of the thing to the oncoming air and slowing down to a near-stop in the process.
Thrust vectoring allows more than that. Compared to the same platform without thrust vetoring, thrust vectoring enables the aircraft to shorten its radius of turn, take off and land shorter, and point the a/c's nose at an angle away from the aircraft's velocity vector -- useful for air to air weapons which need to be aimed.
However, the combat utility of maneuvers which deplete both aircraft kinetic energy and potential energy is open to question. A tail side followed by three back flips and a falling leaf may not be a winning set of maneuvers.