You’re wrong. That person could eat McDonald’s every day and lose weight, as long as they only ate beef pattys. There are tons of videos on YouTube of people doing this exact thing.
When bodies are insulin resistant the only way to lose weight is cut carbs. It’s a very different metabolic standpoint than a healthy body, which can simply reduce calories and lose weight.
“Move more, eat less” is bad advice for someone with insulin resistance and its many complications because it will not work for them.