I run a few groups, like @fediversenews@venera.social, mostly on Friendica. It’s okay, but Friendica resembles Facebook Groups more than Reddit. I also like the moderation options that Lemmy has.
Currently, I’m testing jerboa, which is an Android client for Lemmy. It’s in alpha, has a few hiccups, but it’s coming along nicely.
Personally, I hope the #RedditMigration spurs adoption of more Fediverse server software. And I hope Mastodon users continue to interact with Lemmy and Kbin.
All that said, as a mod of a Reddit community (r/Sizz) I somewhat regret giving Reddit all that content. They have nerve charging so much for API access!
Hopefully, we can build a better version of social media that focuses on protocols, not platforms.
I believe federation only happens from the first subscriber going forward. If you instance is new it may not have got the older posts, but in time it would become less of a problem.
If you’re looking for more content, change your settings to “All” and “New”. New posts come through all the time.