People tend to emphasize the negatives, like you mentioned, but WhatsApp has revolutionized communication in the low-income country I came from. And I think ultimately creating a net benefit for society (even though the conspiracy theories are really bad). Calling/texting using the cellular networks is still pretty expensive, so a lot of mom-and-pop shops conduct a significant portion of their business over WhatsApp (for a fraction of the cost of an equivalent 1-800 number).