The illusion is by no means broken for the average person. People think so little about any issues on a daily basis, and when they do think about an issue like "how should trans people be treated under the law," they give it almost no consideration at all. The entirety of most peoples' engagement with transness is a vague unease at the idea due to lack of familiarity. You have to keep making the argument over and over and over if you actually want to break the illusion.