Grifters, trolls, asshats always find their way into communities that are centrally moderated. That includes most online games and social media today. This problem isn't solved with anti cheat and government ID checks. In fact this problem was solved years ago, simply by letting each community create their own spaces with their own rules. This means some spaces are private. Others may be semi-open. And some will be fully open, and yes that will always be chaotic.
The only multi-player games I play are with friends or their friends, ie people I already trust. The only social media i use is group chats with friends. Of course, you can have more open and anonymous spaces like we have here on HN, but you need more moderation and the moderators need to feel some sense of pride/ownership to keep on working for free.