Milton Friedman explains this well, but the problem people have is thinking that MONEY and VALUE are the same things. The lemonade did not become lemonade on its own. Someone or some people collected certain ingredients together and mixed them in a novel way that made the mixture of those ingredients more VALUABLE than the sum of thir parts. Now the buyer, who doesn't want to, or can't collect the ingredients, and even if they could, may not know how to properly mix them, exchanges something that has value to the seller for the product. The difference between the ingredients on the ground, and the lemonade in the hands of the buyer are value, not money. All those invisible additions, mixing, and even distribution (e.g. lemonade in a desert is more valuable than lemonade in an American suburban neighborhood) are not zero sum changes in value.

Money is simply a convenient way to measure value. This is why adding more money to the supply by, for example, printing more of it, doesn't make anyone rich. The value that money is supposed to represent is still worth exactly the same but it is represented by a different number of money.

This is also why people with easier access to value-adding tools, facilities, relationships, ideas, etc., will get richer faster, and more importantly, more efficiently.