In 19-century Italy, opera was about as popular as pop music today.
As an artist, you certainly can change (some of) the world if you do art which people care about. If you do refined academic portraits, or [adjectives expunged] postmodern art, only a bubble is going to care. If you do art like, say, Banksy, a lot more is going to care. If you sing in classical opera, only a narrow (but usually wealthy) circle of opera goers will care. If you sing like Taylor Swift or like Whitney Houston (who had a powerful, opera-worthy voice), you may have a much wider effect.
As an artist, you certainly can change (some of) the world if you do art which people care about. If you do refined academic portraits, or [adjectives expunged] postmodern art, only a bubble is going to care. If you do art like, say, Banksy, a lot more is going to care. If you sing in classical opera, only a narrow (but usually wealthy) circle of opera goers will care. If you sing like Taylor Swift or like Whitney Houston (who had a powerful, opera-worthy voice), you may have a much wider effect.