Tell that to people unwilling to leave twitter because they are struggling to find content on mastodon. The major benefit of big social media companies is typically that they provide an algorithm to content that people find interesting by paying an invasive amount of attention to what you do on their websites and how you interact with content.

While not everyone is as interested in an algorithms idea of what we would like to see or content we would enjoy, to ignore that many people out there are very interested or to paint it as purely a means of advertisement ignores why some humans are still on these platforms and the source of their attraction.