I think this is a misinterpretation of what has been debunked. Low fat diets are definitely healthier for more people because they almost always correlate with lower calorie intake. It’s not the quality of it being a fat that makes it bad (this is what recent studies revisiting fats are saying). It’s other qualities of fats that are problematic. For example, consider equal calorie intake between a protein source (like a steak) and a fat. Which do you think is going to fill you up more? Which do you think is healthier?

Fat is calorically dense. If you're trying to lose weight, you need to be careful about eating calorically dense foods. And if you want to eat more protein to maintain muscle while losing weight, there is a zero-sum trade-off between fat and protein.