What you say is partly true, however the servos act a bit like power steering in a car. A force on the control column is still required (in the case of non-airbus types) to maintain the correct attitude on takeoff. With an incorrect trim, the stabiliser will be producing an incorrect amount of downforce and therefore the pilot would need to apply an immediate large force on takeoff to achieve the correct attitude. By setting a takeoff stabiliser trim, we are setting a sort of null position for the liftoff speed and therefore making rotation easier and safer. An incorrect stabiliser trim can rotate the aircraft prematurely on takeoff or make liftoff at the correct speed slow or difficult.
Imagine if your car steering wheel was permanently set to hold the wheels 10 degrees off to one side. You could still steer as you have power steering right? But it would be a major pain in the neck and a bit unsafe as you would have to constantly apply a force to drive straight on? Same idea with trim.
Trust me, takeoff trim is important!