Did you use Twitter much before then? Some people just don’t like the format. I use it to get updates on some things, but I don’t use it as much as Lemmy (or Reddit before that).
If you did use Twitter, perhaps the content you followed back then still didn’t make its way to Mastodon (or it went to bluesky/threads?)
Last thing you could try is following more people. I find that fediverse platforms need you to seek out content more actively, while old profit driven social media platforms were constantly seeking engagement. On top of that there just isn’t as much content on any of the new platforms compared to the older ones.
That all being said, the quality of the content is equal or better every time