I’ve found almost the exact opposite.
Engagement on Lemmy is mostly fine, but I chat with people all the time on Mastodon
I think the key is to meet people on their level, to find people who share your interests and sensibilities. Follow plenty of folks and chat to them and before long you’ll have a grand little community.
Over on Twitter I was keen to chat to people with large follower bases in order to perhaps hook in to some of that. On Mastodon I generally have no idea how many followers people have because it really isn’t important to me any more.
If someone is interesting, and their engagement good, then I’m happy to be a follower.