What if communism was never introduced to the world?

There would be no welfare, no minimum wage, no social security, no decent  healthcare anywhere in the world. Child labour would be commonplace everywhere. There would have been no limit in working hours, or overtime payment, and we'd work 12 hours per day. The rich would have been richer and the poor would have been poorer. Up to here anarchists are also responsible (they can be considered communists in the sense Marx used the term anyway), and to a lesser degree, other socialists.

Also there would have been no government-owned industries or services nor any economic planning. No working class-based parties or politics. Even the 'working class' itself is a communist invention. Until Marx there were 'working classes' which were thought to have little in common, not a single self aware political subject. In many countries, women wouldn't have had the rights they have today, or they would have gained them only recently in many places. Many a third world country would have emerged from imperialist rule much later, if at all.

Nazis would have invaded Europe and have dominated it (without the Soviet industrialisation no way in hell Soviets would have won that war). Millions would have been killed. The map of the world would be quite different. On the other hand, considering how much the fascist movement owes (i.e. stolen from) to the communist mass-mobilization politics, maybe there would have been no nazis in the first place, just some typical repressive conservative regime instead.