Japan had an entire lost generation of people (mostly men - but then women as a result of Japan's strong monogamy correlary), who were largely left to rot and fend for themselves (Yagoo's generation btw - he was just one of the one's who 'made it'). Yagoo sees the same thing happening again, but this time on a global scale. He understands that idol culture (which is unique to Japan) can be used to provide people who have been abandoned by society an emphatic voice and sought to use his tech to spread that through the world. That's why he hires these slightly broken people - because such cracks are what develop a person's ability to emphathise with others.

It's not about therapy (insofar as therapy is about healing): They represent a release from the 'normie' paradigm and allow you a sanctuary to exist in with others of like mind who actually value you, because they're capable of seeing you as a human. The fact that Yagoo is an ideologist should be obvious from the way he champions Holostars (which provides the same for females - which have the same problem albeit only in Japan currently).

It's not that hard to understand and it's not purityfagism. It's the literal stated goal of Hololive. Some of you self-hating fucks just won't admit it - because you can't bring yourself to believe that it isn't just for money or for a career jump. It's for people for whom "therapy" doesn't even apply and who are invisible to the world. It's suppose to give you something to aspire to: to encourage you to better yourself. Even if it means not necking yourself because you want to watch your oshi for one more day. It's not a solution, but it's medication to sustain you whlist you sort yourself out.