Every system has certain rules and principles. We tend to think that whatever rule there is will continue being correct for all scales but that is not the case. The most notable example comes from physics. Classical physicsl vs Quantum physics. Anyone familiar with it will know that the rules of the game is completely different for both of them.
Another example comes from biology. The cells in our body live by different rules than us humans. And us humans live by different rules than human societies (companies, countries, humanity). As the scale changes the rules change. A notable example of this is individual humans trying to tackle global warming. This is like a cell in my body trying to fix my relationship problems. Each scale can only solve its own problems. Cells can solve organ problems, organs can solve human problems, humans can solve society problems and societies can solve global problems. So someone who knows this mental model, will not try to fix the earth but instead work on upgrading its company or country as in education, economy, etc. whatever that entity needs.
Another example of scale can be used in Economics.
Another example comes from science. A scientist giving 4200j to 1kg of water which sits at 10°C will observe that its temperature has increased to 11°C. Then they give another 4200j and it increases to 12°C. Another 4200 and it increases to 13°C. The scientist continues doing this until it reaches 30°C. And the scientist concludes that to get the water to reach from 10°C to 1000°C he will need 4,158,000j. But in reality the water goes upto only 100°C and then starts evaporating. Which shows that methods also change rules when they are scaled.
Another example of method comes from startups. Initially the founder can write code everyday to grow their company 1% every week. But once it hits a certain number the rules will change. At a certain scale the founder needs to stop writing code and start hiring people to continue progressing.