Maruyama Sensei says in Aikido we are trying to Beat ourselves, Not others.
Grading plays an important role in measuring progress in your Aikido Journey. This is a place to demonstrate how you have grown in the time since your last test.
Bur grading is not a stepwise progression. You do not need to get better when you are asked to do your grading. Think of it more as a pathway continuing off into the future and you have been asked to mark a milestone.
The reward is often another Kyu rank, and you may get to wear a new coloured belt, but the a actual test is a chance to take centre stage and highlight your progress.