We have to make choices because of scarcity.
Woah. That’s a big word.
scarcity.
What it actually means is : there’s not enough to go around.
First obvious problem is, we do not have enough money to buy everything we want. Thus, we have to make choices.
Why do we not have enough money? Because The employer that pays our parents do not have enough to pay.
Why do the employers not have enough money to pay? Because the people who buy their products and services do not have enough money to pay more than they can afford. The cycle goes on.
So everyone has to make choices because of scarcity.
FUN FACT : Everything is scarce, not only money.

Water is scarce. The more people we have on this planet, the more we have to fight for the limited amount of fresh water we have.

Food is scarce. There is a limited number of food plantation, cattle, poultry and fish in the ocean.

Time is scarce. We only have 24 hours per day every day, we cannot have more than that.