It's certainly more complicated than that. I spent a year and a half trying to be in a calorie deficit, meticulously tracking every calorie and wasn't able to lose weight, because I wasn't able to stay in a calorie deficit long enough.

Recently switched to keto, which has the primary function of lowering insulin levels and reduction of feelings of hunger. And within 2 months I'm 18 lbs down.

It's not simply a matter of Calories in/calories out, the kinds of calories you eat matter. 2000 calories of donuts vs 2000 of beef are vastly different nutrient profiles and you will have corresponding health effects accordingly.