Realize though that rich..poor is not static but very dynamic with people rising up and falling down all the time.
The method in the free market is subjective value signaled by prices. When you work you exchange your labor which you value less than you value the compensation earned that you feed, clothe and shelter yourself and family with, and go on vacations and buy mororcycles. Who determines your compensation? You and your employer each subjectively.
If someone else, say the government, steps in and sets prices, wages, etc, it distorts the market for goods and services and labor. It creates shortages or gluts.