The 'successful'* accounts here are those that embrace our community best practices (good hashtag use, alt-text on media, CWing sensitive topics, etc.) and put in some effort to chat with people and make friends, reply to comments, and interact a lot.
The accounts that complain that 'mastodon is dead' or 'the fediverse is bad for artists' are those who just post their stuff but don't bother following anyone or getting to know their neighbours.
Good account examples in the next toot: