Consider the application of Right Thrust as "Engine TRim" if you will.....That your powered plane has many built in effects to cause it to "go left" RIGHT thrust is to correct for these built in features so that the plane is neutral in all axis when the plane is perpendicular to the ground........Now of course getting the plane straight up and down ....correction for wind and power....wing....all sorts of other things that the pilot must correct
for as variables is the fun part.....Just like a heli hovering...if you're in that sweet spot...it will sit there....BUt that doesn't mean it doesn't need correction to stay there