Hololive is just one example within a specific niche (and even within VTubers it's not the only one -- Nijisanji is pretty large as well now). Are you really telling me that people like Amouranth, Valkyrae, and Pokimane aren't aware of the girlfriend experience? That the whole hot tub streaming drama that led to the creation of an entire new Twitch category wasn't extremely exploitative of lonely, addicted men?

Unhealthy parasocial relationships are an extremely lucrative revenue stream for content creators, just like whales with gacha games. Platforms do nothing to discourage this and in fact even encourage it.