Why it works this way
A leaderboard only feels good when you recognize the names on it. So groups are invite-only, steps sync automatically from the health platform you already use, and there's no public profile, follower count, or feed to maintain. Join a group, join a challenge, watch the board move.
That's the whole feature set on purpose. No streak-shaming notifications, no ads competing for your attention, no data broker in the middle.