This is true: Vampire produced some really obsessive behaviour and, LARP, well, LARP intensifies everything.
I've got something in my brain about #ttrpg players and parasocial relationships, but I'm not in the right headspace. We've all witnessed the rise in a parasocial relationship with D&D5e alone, buoyed by Critical Role and a few key others. But that pales in the shadow of Vampire: The Masquerade.