Who does he think he is / do people actually respect his opinion.

If someone like JoJo said this, it would make sense. They fd up her career. Record labels can help boost artist’s visibility. Most the stuff like radio, YouTube, Spotify….all those suggested playlists and music/videos that playing on auto - that’s not random. Independent artists don’t get that sort of luxury so yeah it can be worth it to get signed. But it doesn’t mean guaranteed success. People either like you / your content or not