Indeed, economics end up being the study of resource allocations by human beings, both at the individual and collective levels, and the resulting system.

But macroeconomics is indeed based on a lot of things, and you seem to be very misinformed. Macroeconomics relies very heavily on mathematical tools such as calculus and topology to model the collective behavior of humans.

If you are really interested in learning more, I recommend "Knowledge and the Wealth of Nations: A Story of Economic Discovery".

Math is a language, it doesn't make something scientific (or not scientific). The issue of math and science are unrelated. The problem with macroeconomics is not the tools they use, it is that it does not have predictive power. We cannot meaningfully (better than martingale or historical MA) predict GDP/inflation/SP500 return etc. A lot of macro assumptions are obviously wrong (people do not optimize marginal utility, people have transitive preferences, nobody can meaningfully compute externalities of basically anything, etc)..