>>7180811They're another form of social interaction, while the relationship is asymmetrical and some call it parasocial, it's still something that fills the hole many people have from having trouble making meaningful connections with others. People are lonely for many reasons in their life, and vtubers, who often are also lonely people expect more proactive, provide a pretty solid alternative you don't have to fully commit to if you don't want, overall a mutual exchange of attention from people not fit for more standard social interactions otherwise.