Some things about your application are already fixed by the time you sit down to write your essays. Your GPA. Your test scores. Your work history. Those numbers are what they are, and there’s little left to do except present them in coherence to your overall story.
Your essays are where the real work sits. This is the one place in your file where you stop being a set of numbers and become a person, where your upbringing, your values, and the things that actually shaped how you think finally get to matter.
The topic you’re avoiding, the one that makes you blink at the thought of writing it, is very often the one that would make you memorable.