Yes, you're right, but you have to look at the others—people like Meilang, Chaochui, and Lute. Their ages are genuine, and the details provided by the AV studios are real too; after all, they worked in the AV industry before becoming VTubers, so there's no point in trying to hide it. If Ran is actually Sakurase Na, wouldn't it be awkward for a 40-year-old to be sitting alongside a group of people in their early twenties?