@Mastodon unlike many others responding here, I’m OK with the default onboarding of the official app going to the mastodon.social server. That’s an experience the Mastodon org can control and make work well. I haven’t seen any better suggestions and clearly the current setup is confusing.
Round robin could potentially be worse: randomly ended one place or another, and with subtly different rules. I found filtering by interest bad too: many have broad interests.