It's not the same as having friends over. You play with your friends. They're having their own experience, and you're having yours. Streamers get to have other people share that experience.
(To `moretai's downvoters: Yes, we can read their comment as an insensitive, unimaginative put-down of this group of people. But why should we? I think there's an interesting point to be discussed here, and I'm more than willing to read `moretai's comment as a genuine question.)
Top spots nowadays are claimed by sponsored players anyway and making it as an amateur is nightmarish difficult. Fame grows exponentially because once a talent emerges companies are quick to sign it up and after that they provide most of the promotion for their talent to grow.