I know that the net calories consumed/burned is what determines my weight, but the benefit of a low carb diet (only speaking for me) is that I am not hungry. I lost 50 pounds in the first six months and have been at the same weight for 18 months.

There's a bit more to it than that.

First, it's calories absorbed, not consumed. That is, if I eat calories in a form that's harder to digest, my body may not get all the calories out of it that are in the food. I think that this is one of the deals with processed food - the processing makes it easier for your body to extract the calories from the food. The calories were already there, but they're processed into a form that your body can use more easily.

Second, some foods (at least for some people) have some effect on metabolism, so that calories consumed is not totally independent of calories burned.

Well, you are "anti-conflating" the latter and former. They are describing the same mechanism, not two separate ones.

The point is that carbohydrates are calorie dense. You don't need to eat a lot of them to get a lot of calories.

Fish is one of the least calorie dense meats. Vegetables and fruits are some of the least calorie dense foods. It's nearly impossible to eat enough lettuce in a day to go over your daily recommended calories. It just won't fit.

So, in a lot of ways, keto, paleo, vegan, Mediterranean diets are all sneaky ways to cut out a major source of calories. You don't have to count them because just the way you're eating is taking care of that aspect.

But if you want to eat Twinkies exclusively, you can do that as long as you eat only so many.

Fat is more calorically dense than sugar, and your examples are all low in fat as well - vegetables and fruits have more carbs than either protein or fats - and the high calorie examples (ie. Avacado) of those categories are high in fat. Fish has few fats and no sugars. The most calorific cuts of meat aren't that way because they are sugary, it's because they are fatty. It's just that fats lead to satiety quicker than carbs, but I'll bet if you ate pork belly for every meal you'd find that you could and would get fat on that.

I didn't say they excluded all major source. I said a major source.

Yes, paleo and keto (I think) don't exclude fat, but they are excluding a major source of calories. Because we do need some fat in our diet or else we go into rabbit starvation.

There's nothing really in bread or refined sugar that we need that we aren't getting from somewhere else.

Fat is 2.25x as calorie dense (Cal/g) as carbs.

And? We already eat fat pretty sparingly. Whereas with sugar, you can color it and fluff it up and people will eat a giant cloud of it.

So, when you point out where I said those diets cut out all major source rather than a major source, feel free to continue.