You are describing a real world scenario of drinking fruit juice versus eating the equivalent fruit, and the results are stunning.
> But would the latter really affect you vs. a meal without carbs?
Yes. The body will prioritize sugars, and thus carbs, over fats in both processing and energy extraction. That is problematic in that the rapid processing of sugars produces a result similar to a stimulant drug while consumed fat is just stored without use. Dropping carbs has allowed me to feel focused constantly without need for caffeine and minimizes sensations of hunger.
I have trouble parsing exactly what you mean here, but it feels like a misunderstanding. Do you think consumed fats just sit ignored in your gut until any carbs are digested? Or that all fats consumed coincident with carbs are necessarily stored in adipose tissue? Both are absolutely not the case.
Your body must make a choice on what to process because different processes and hormones are involved. Sugars are always preferred because they have a lower cost of execution resulting in higher net energy. That means fats consumed at the same time are either stored or discarded until all sugars are processed.
That is ideal when food is scarce, sugars are scarce, and high energy output is frequent. Today high energy output is rarely demanded and sugars are abundant, which results in weight gain and obesity.
There is also encoding in the brain that drives a preference for sugar energy. Sugar is more physically addictive than cocaine, for example.
A high fat and low sugar (carbs) diet can be harder on the heart but it results a fairly constant body energy without the ups and downs of sugars and stimulants. It also results in weight loss. The body is smart enough to know how much fat it requires from food for energy output and discards excesses, but that body intelligence is confused by exercise.
The notion of binary carbohydrate vs. fat metabolism is not reality. You're always using some of both, the balance just shifts dependent on a whole host of factors. Further, this has little to do with what happens to ingested nutrients. Fat and sugar are digested concurrently. You gut doesn't "decide" not to absorb fat, or to shove it into adipose tissue (there's no pathway for his; fat has to be digested before storing) because there was carbohydrate in your meal.
The comparison of sugar to cocaine is absurd. I don't have the will to try explaining it right now, but I urge you to read the literature on the subject, not write ups by bloggers/journalists.
Also consider that sugars in the blood cause a pH imbalance, and if they are not rapidly metabolized this causes damage to our organs (and diabetic symptoms). You could make the same argument that fires are a priority in the kitchen because a cook will address them first.
> But would the latter really affect you vs. a meal without carbs?
Yes. The body will prioritize sugars, and thus carbs, over fats in both processing and energy extraction. That is problematic in that the rapid processing of sugars produces a result similar to a stimulant drug while consumed fat is just stored without use. Dropping carbs has allowed me to feel focused constantly without need for caffeine and minimizes sensations of hunger.