Correct, use VoIP with wi-fi service instead of cell and data. It also makes the calls untraceable for location for best privacy practices. There’s no way to trace where in the world a phone is if using wi-fi to call standard phone numbers. For personal calling, not a work phone, some people don’t care about messages and calling when they are out walking, shopping, attending events. They want to focus on the real world around them, not phone stuff.