It is literally within the formal definition entropy. Debris is a high entropy macrostate, while a car occupies a lower entropy macrostate. There are less possible atomic configurations for cars then their is for debris. Each of these individual configurations of atoms is called a microstate.
A macrostate is a collection of microstates that you define. Depending on the definition you choose that definition has an associated probability. So if you choose to define macrostate as a car, you are choosing a collection of microstates that have a low probability of occuring.
The law of thermodynamics says that systems will, over time, will gain entropy meaning they naturally progress to high probability macrostates over time. So in other words, complexity is destroyed over time by specific laws of entropy.
https://en.m.wikipedia.org/wiki/Entropy_(statistical_thermod...
The reason why this occurs is straightforward. As a system evolves and randomly jiggles over time it trends towards high probability configurations like "debris" because simply that configuration has a high probability of occuring. Generally the more billions of microstates a macrostate contains the higher entropy that macrostate is.
Through logic and probability and the second law of thermodynamics we have a formal definition of complexity and we see that complexity naturally destroys itself or degrades with time.
This is the thing that confuses people about entropy. It's definition is a generality based on microstates and microstates you define similar to generics in programming. But even within this generic world their are laws that tell us systems trend towards losing complexity. The heat death of the universe is the predicted end of the universe where all complexity is inevitably lost forever.
That doesn't really line up logically. :/
Debris is almost any configuration of atoms that are considered trash or unusable.
There's are much more ways you can configure atoms to form useless trash then you can to make cars. Case in point "you" can manufacture "debris" or "trash" by throwing something into a trash can. Simple.
When's the last time you manufactured a car? Never.
Seems like a case of you including and excluding things to support your "logic". Ugh.
Is this not a linguistic sleight of hand? There are billions of trillions of states we label with "debris" but only a few thousand we would call "car". So a specific state of debris, then, is equal in complexity to a car?