For the moment, when Lemmy can connect to tens of thousands (MAUs), & Kbin can connect to millions (MAUs). Personally I'm going to go with my Kbin account.
Both platforms need development. Also other forum platforms are taking up ActivityPub #NodeBB#Flarum#Discourse so this space on the Fediverse is going to expand & evolve quite a bit. #Fediverse#RedditMigration