Elvis came from an extremely poor background in the deep south of the US. The family really had nothing.
He was the first real rock star and kicked down the door for others to follow. He became huge very quickly under Col Tom Parkers guidance and at a young age. What happened to him had never been seen before; he was considered the devil, obscene and the main reason for juvenile deliquency all over America. He was attacked on all fronts from all quarters.
(His Sun Recordings before he hit big imo are some of the greatest music ever made and showed his true genius-compare those recordings to what was popular in the charts at the time!!!! it's like music from another planet)
Elvis was very grateful and hugely respectful of Parkers judgements and decisions, because of his poor upbringing he was haunted by the fear that he would one day lose it all and go back to nothing. Before the making of Clambake in 1967 he had made the decision that once his movie contracts were up he was going back to live appearances and possibly the line of
soon be back in Memphis is when he was more or less finished with the movies and had made one of the best albums of his career in 1969
From Elvis In Memphis and had recorded many more great songs at these sessions in Memphis. By the 70,s Elvis was standing up to the Colonel and just before he died, he was considering sacking Parker. By then Elvis was a complete mess due to prescription drug abuse.
I believe without Elvis there would have been no Beatles/Stones and many others that followed him.
Christ we could be listening to Perry Como/Bing Crosby type music without his impact.