Between 1920 and 1930 Germany was no where near the most powerful country in Europe. Unemployment was the highest in Europe and things were quite bad even before the 1928 crash. https://en.wikipedia.org/wiki/Economic_history_of_Germany#Early_20th_century

https://en.wikipedia.org/wiki/Economy_of_Nazi_Germany

Meanwhile, Schacht’s administration achieved a rapid decline in the unemployment rate, the largest of any country during the Great Depression. By 1938, unemployment was practically extinct. Price controls kept inflation in check but also squeezed out small farmers. The government also introduced rent and wage controls.