The food pyramid went away over twenty years ago. It was discontinued in 2005, and the current guidelines are at https://www.fns.usda.gov/cnpp/myplate which launched in 2011.

I consider the traditional food pyramid, with grain at the base, to make a lot of economic sense.

The question is not "what's best for you", but "how to keep as many people as possible well fed and reasonably healthy". And an important part of it is that everyone gets enough calories, even the poor, and even during hard times.

Grain is an efficient source of calories, and grain products tend to have a good shelf life and don't need refrigeration. And ideal baseline for keeping people from starving.

But grain is good for calories, but not enough to keep people healthy, you also need vitamins, fiber, etc... So you introduce the second food group: fruits and vegetables. A bit more expensive and more involved than grain, but it provides most of the things grain don't.

Now, we are at a vegan diet, and experience has shown that it can be perfectly healthy, but in order for it to be, you need to do a significant amount of bookkeeping, and you may need some slightly exotic food to avoid deficiencies. So, not enough for the general population, so you introduce animal products. Even more expensive, but now you have everything you need, with good margins.

The top of the pyramid is for the products for which the needs are covered more efficiently by the lower layers.

"Pretty much everyone I know understands that the food pyramid is the product of various lobbies"

Maybe adults, but probably not the people who were taught the food pyramid - children.

Edit: changed the tense to acknowledge this was in the past. Thought that was obvious since the food pyramid was a thing of the past.

Don't public school lunches have to follow the food guide recommendations? Assuming that hasn't changed since I was in school, a recommendation based on something other than industry lobbying could help quite a bit with children's health and long term outlooks.

That said, I obviously don't know what this administration would propose as a new recommendation so I'm not implying it will be better. We'd have to see what they put out, if anything, to get an idea about that.

Source?

I think the real problem is that a food pyramid is an oversimplification.

No matter what you do, “fruits” isn’t really a goal — it’s macronutrients and micronutrients like vitamins, fiber, etc.

So with or without lobbying, any food pyramid will always be wrong. A food pyramid exists because it is far more relatable than comparing nutrient labels and tabulating.