Looking back, why do people believe the Beatles were such a massive success in the United States, changing pop music forever?

The Beatles were very successful in their career because of pure talent and aggressiveness in their ambition. These are the main ingredients in order for anyone to be successful. Because of these traits, they somehow made a new taste in music, captured the interest and hearts of the people, and continued making tasteful music to satisfy them. Their innovativeness in music brought change to pop music forever.