Rich people tend to have most of their worth in stock. In theory, assuming your stock got more expensive, you get richer without anyone in particular getting poorer.
edit: Ability to pay grows with inflation, by definition. Unless you have a particularly unusual type of debt, the principle is constant and the interest is based on the remaining principle and is therefor a pre-inflation value. Wages grow in absolute terms (even though their purchasing power is otherwise constant), so the debt is easier to pay off.
Getting richer has a strong relationship with making others poorer.
This theory is naive, dismissive, and wrong. You have accurately seen some bad examples, and it has led you to incorrectly conclude that the bad examples are the bulk of what is going on.