The problem, I’m a picky eater. I never order something that simple. I always need it with “No X” or “Only Y”. Cashiers often struggle with that, even if they understand me well (which they don’t always). It’s easier for me to see everything an item comes with and make sure I’m entering my order correctly.
Then why are you eating at McDonald's?
McDonalds' menu is not designed for folk like you. In my part of the world, we had traditional fast-food joints where the question would be inverse: out of the things you can see and add to your burger, pick a few. That is very efficient with a human prepping your burger.