If you’ve traveled extensively you’d know that entire countries depend on WhatsApp for communication. It’s free to use for many people as part of promotions with their cellular providers. Even government offices will use WhatsApp instead of sms. It’s going to be incredibly difficult to get them to switch. So you saying “whoever uses this piece of shit software doesn’t care about privacy or anything else” shows your ignorance. Some people don’t really have a choice due to their situation.