This is a qualitative/irrational assessment and not a quantitative/rational one, especially considering that fat consumption got a wrongfully-deserved bad rap for decades thanks to unethical lobbying by the sugar industry.
I’d argue (based on the best dietary research the world has produced) that saturated fats do deserve a bad rap, and most refined fats are also worth minimizing in a diet. Are all fats bad? Not at all, we should eat them. We’d die without them. Are saturated fats and refined plant fats worth including in our diet? Arguably no, not at all. Incidental consumption of them is more than enough and intentional consumption becomes problematic quite quickly.
I’m not aware of any outcomes-based studies spanning the globe which indicate that a high fat diet serves most people well as far as long term quality and quantity of life. On the other hand, there are several, and more all the time, showing the opposite.
The valid “fat is actually okay!” data almost exclusively comes from whole-food based studies. However, those which position saturated fats as safe or healthy are typically of poor designs. One example off the top of my head is one which put vegetarians on an extremely high coconut oil diet and meat eaters on a lean meat diet. The results? Eating meat is better for your cholesterol! Surprise?
I couldn’t make this stuff up. In fact, someone likely paid people a lot of money to make it up. The irony is that it uses the truth (saturated fat raises blood lipids) to indicate that this truth is actually false. If saturated fat was bad, wouldn’t the intersection of meat eaters and vegetarians look different? It must be okay. Makes a great headline!
I agree that the sugar lobbying is absurd and harmful to society, but you’d be doing yourself a disservice to believe there isn’t a massive and busy lobby behind fats as well. Why wouldn’t there be? Look at how many studies around animal products and fat are funded by associates of the food processing industry.
And yet the best studies we have clearly have no commercial agenda behind them, they typically took years or decades of work, yet they’re hastily discounted by all kinds of people.
diet is a fairly complex topic and it's a shame that most doctors don't get more than a single course in nutrition. I read a paper like this (which is related to our discussion) and the raw complexity is just... difficult to boil down into a variety of good food choices sometimes: https://openheart.bmj.com/content/5/2/e000871