Why arent all people paid the same amount in factor payments for the resources they provide?

I was taught under Capitalism System Doctrine, "If everybody was paid the same, it would cut into the profit margins" and "If everybody was paid the same, inflation would be uncontrolable", which would also cut into the profit margins. The reasoning being on the inflation issue, the greed factor would quickly drive the cost of goods and services pass the total income's complete saturation point. Making many goods and services unafordable. "All people" would have limited purchasing power choice between their "true needs" and/or their "Compfort items".

Under Capitalism System Doctrine, underpaid and/or poor people are necessary, forcing goods and service providers into terracing measurable quality, and pricing, keeping inflation in check. This also, and perhaps more importantly, vastly increases the political and economic power of the privately owned Federal Reserve banking system and political, economic and purchasing power of the wealthy verses the underpaid and/or poor's diminishment.

In economics, factor payments are the income people receive for supplying the factors of production. Land, Labor, Capital, and later was added Entrepreneurship to the "factors of production".

I do not give a full answer. I merely point out that away from the text books and in the real world, causes and effects are governed by System Rules and that these System Rules have been manipulated and honed over time to produce a certain outcome.