The only way people get paid out is with an ever increasing supply of new cash.
So what? So long as there is an ever *increasing* supply of goods and services.
You don't need to contemplate money here. Look at it in pure terms of raw natural resources. A company takes a certain amount of labour, and a certain amount of land, and a certain amount of material, and uses all of that create something new that never existed before and which has real value. It is now worth, in raw material terms, more than it was.
This is true whether or not your economy includes "money".
Money simply makes trades more liquid. In an economy with money, such as all modern economies, if you did not increase the money supply you would face *deflation*. That is because businesses would create ever more value, and so you would have the same number of dollars chasing after a larger number of goods and services.
As a result the money supply should increase in line with the creation of new goods and services, so that the proportion of dollars to goods remains roughly constant, or at most increases by a predictable amount (a flat, predictable rate of inflation).
The market does not magically increase the money supply.
Actually, it does.
It is simply a bunch of assets that change hands at varying prices that do not always go up forever like an endless pyramid.
No, actually new assets are created over time. That is what businesses do: They create goods and services (aka, assets).
Stock buybacks are not a transfer of wealth to shareholders.
Stock buybacks are mathematically equivalent to dividends. The only different is one of expectation--you expect a stock buyback to be a one time event, whereas you expect a dividend to be a regularly recurring event. There are also tax differences.