No, not necessarily. Mastodon is actually "social media", as opposed to twitter/X, bluewhatever, facebook, or any other commercial outlet, to be honest, all of these have become "feeds" of promoted content designed to maximize "engagement".

Mastodon is social: you follow people, you see their stuff. It's what social media used to be.

You’re posting that on HN. I consider HN to be social media but lacking the most pernicious features (ads, algorithmic feeds) and benefitting from both strong moderation and self-policing. But it gets to do that by being funded from extrinsic sources, which is itself a compromise.