up until yesterday i had assumed that the total amount of money in the world is zero ($0) because what one person has in bank account, another person has in debt at the same time, since money is literally nothing else than a codified form of debt.

Nah, money is constantly growing. Whenever anyone does anything of value, there is more money. People are alive and doing things every second of every day. Unless there’s a catastrophic bubonic-plague level event, the total value of money in the world is constantly increasing.