One factor which is also somewhat important isn't technological but social. Atmosphere and game culture matters a lot. In a supportive environment that doesn't tolerate stalking, grooming and other abusive behaviour, stalkers, groomers and abusers will be rarer.
Whereas in a toxic community where no one gives a fig in the name of 'free speech', the people who are considered prey will leave. For me, the turning point that made me leave WoW, for instance, was exactly that: I realised I spent one hour in eight actually -roleplaying- and the rest of my communications with other people were either helping them deal with someone being toxic at them, or watching people be toxic at me. Every public statement anyone made seemed to attract a horde of rabid alt-right recruiters, every female had a following of males either trying to get in her pants or telling her off because fuck girls the internet is for porn. The game became a hotbed of extreme rightwing politics, blatant racism and sexism, and Blizzard's infamous stance of 'not violating our community standards', a concept they take to almost Zuckerbergian levels.
At some point it's just enough. People, the sane people, dropped like flies. My friends were gone or leaving. You get off the sinking boat, leave it to the numberchasers and the edgelords trying to out-nazi each other.
TLDR: The first hurdle in preventing online abuse is to create a community in which abusers do not feel welcomed.