Equality, not inequality. Countries where income is distributed more equally are wealthier than countries where income is distributed more unequally. Equality increases supply and demand. When everyone is equally employed, skills improve and product quality increases. Equality increases demand because full employment increases effective purchasing power.
Inequality reduces supply and demand.
It reduces supply because underpaid people produce less and goods of lower quality than well paid people. Unemployed people produce nothing. Inequality reduces demand because underpaid and unemployed people lack the money to buy what they need. Increase wages and salaries to a larger share of the Gross Domestic Product. Economy, not waste.