That's not macroeconomics, that's classical economics. You do not get macroeconomics by applying microeconomics to everything at once.
Macroeconomics is concerned with things like money, interest, employment, and aggregate supply+demand of whole economies. Macroeconomics became popular once it became clear the the classical theories couldn't remotely explain the Great Depression. You don't get a 25% aggregate shock because people stopped innovating or a production glut or "illusory growth" or whatever the Internet libertarian crowd feels like blaming today. In the classical theory, you don't get people starving because bankers misjudged their balanced sheets because classical theory is not capable of explaining how the two are connected.
You really should read Wealth of Nations if you haven't. There are several macroeconomic trends that he retells from 300, 500 and almost 1000 years ago.
Macroeconomics is concerned with things like money, interest, employment, and aggregate supply+demand of whole economies. Macroeconomics became popular once it became clear the the classical theories couldn't remotely explain the Great Depression. You don't get a 25% aggregate shock because people stopped innovating or a production glut or "illusory growth" or whatever the Internet libertarian crowd feels like blaming today. In the classical theory, you don't get people starving because bankers misjudged their balanced sheets because classical theory is not capable of explaining how the two are connected.