Rockets can also have natural stability due to the relation between Center of mass and center of aerodynamic pressure. Like an arrow or an airplane. A big advantage of using nozzle gimbals is that stability characteristics can be imparted at low dynamic pressure AND control the rocket attitude and trajectory. All without the extra drag and weight associated with fins, or with stabilizing and steering thrusters. But of course fins are only effective for atmospheric flight, so space vehicles will require one or more of the other steering, stabilizing and attitude control systems available.
That is what makes the Estes rockets I built and launched as a kid seem rather simplistic in comparison. But still, I thought they flew pretty straight!