How would the last century have differed if Einstein had not been born?
I believe it was Einstein that initially encouraged America to develop the atomic bomb. Obviously the allies would still have won the war if development had started later, but the circumstances would have been different. As for his work on the theories of relativity, who knows? It’s all very well saying “someone would have developed the theory anyway”, but there’s no doubt that Einstein was a genius and well ahead of his time. Our knowledge of relativity and probably quantum physics as well would probably be significantly reduced. The knock on effects could be massive. Trivial things such as CD’s may not have been developed in the 20th century.
