According to this post, most social media content is produced by professional creators these days.

The reactions all missed the underlying shift behind the move: Social media feeds, once filled with content from ordinary users, are now programmed primarily by professional creators. These creators need identity verification, customer service, and visibility boosting. And they’re willing to pay. Meta is simply filling the need.

(https://www.bigtechnology.com/p/social-media-is-changing-and-paid)

Does this require a reconsideration of what defines social media? Professionalism is not how social media was built, but it is what Meta and Twitter are becoming. I think this illustrates the differences that can be found with platforms like Mastodon & Micro.blog quite nicely.