Because it finally forced the rest of the world, especially the United States, to pour resources into space research that the Capitalists, who solely function on a profite incentive and not the common good of humanity, would have never done it by themselves. The Communists achieved their primary objective. To venture onto the space exploration.
The capitalists were interested in space flight but only as a means to belligerent ends. MW 18014, the first handmade object to reach outer space, was something that Axis scientists and their neoslaves designed as a weapon of war. Later, Imperial America’s dictatorship of the bourgeoisie wanted space flight so that it could spy on the Soviets (allegedly in case they launched a ‘surprise attack’ on Imperial America):
Eisenhower welcomed Sputnik’s launch because it quashed numerous legal concerns that he had about overflight.
Presently, many Westerners dismiss the space race as a series of vanity projects. The knowledge that Sputnik was a relatively ‘primitive’ satellite has bolstered this notion. But without satellites, telecommunication as we know it would cease to exist. It would be a nightmare for almost any moderner.
Without Sputnik, we couldn’t be talking to each other right now. The Communists really connected the world!