Then money must be magic because GDP keeps going up.
GDP goes up because production of goods and services are going up. They are all paid for, however, resulting in a zero sum.
The fact that they are all paid for does not make it zero sum.
Zero sum is an aspect of game theory that says that every gain is balanced by a loss for another person.
And it is.
If I provide labor (physical or mental), that takes effort on my part. I lose my physical time and energy. That is a loss to me - the money I am paid is a gain, exactly equal to the loss. Therefore the sum of the liability of losing my effort and time and the gain of my income is zero.
It is not "zero sum" in the sense that there is a net production of goods and services. Take a coal mine, for instance. The coal in the Earth is useless. When the miners take it out and make it available for use - then there is a net gain of usable natural resources. But that gain is balanced by the miner's labor and by the mine owners investment risk - both of which take time, effort, and/or expose one to liability (the miner may lose an arm - the mine owner may not profit and go under)
GDP is the measure of total market value of an economy, and is not zero sum, because it is actually possible for everyone in the system to benefit. If one person gets a bigger piece of cake someone else bakes another one.
We can't make an infinite amount of cake, that should be obvious. If someone can make 5 cakes an hour, maybe if they have some automation they can extend that to 20 cakes an hour - but then, they still can't make more than 20 cakes X 168 hours = 3360 cakes per week, can they? And even that is without sleep. Sure, someone might be in the background investing in technology that would boost that person's output to 25 cakes an hour - but if that person is told to make more than 3360 cakes next week, they physically cannot.
Unfortunately, as you know, our economy is actually far from maximum production levels. In fact - at first at least, as the number of workers fails to replace the number of retirees grows every year - it will be positively beneficial, as it will put people back to work. The baby boomers will be tapping not only their SS income but all their other investments as well, and as they retire, the unemployed will take their place.
But at a certain point, when retirees exceed workers to such a degree that demand cannot be met - prices go up.
Here's another example - there is a peak rate
right now at which oil can be extracted from the ground -
and - there is a peak rate at which that speed of extraction can increase.Maybe the oil industry can extract X bbl/yr right now, and maybe they can extract Y bbl/year/year for every year after - but if the rate of increasing demand for oil exceeds X + Y*t - the price MUST go up.