Instagram seems like their most engaged property. FB seems to be devolving into groups + marketplace, and WhatsApp gets a lot of play but I don't think it's the best ad serving/bot surface. I don't think Insta alone can carry the company long term, and while I can see group moderation bots, marketplace agents and insta content assistants being popular, I don't think Meta has an entre into running people's lives the way Google does.