Remember: Mastodon moves more slowly than Twitter (network-wide conversations seem to have a much longer tail), and there's no algorithm to suggest people/toots to you (overall I think this makes interactions/relationships more stable, but it does raise the barrier to entry).
It took me a few months before I started to find my home timeline consistently interesting. But now that it's there I find the discussions I have/read on Mastodon far more rewarding than what I have on Twitter these days.