Most people, by themselves, have very little say in what messaging apps the people that they need to talk to happen to use. They have people that they need to talk to, and they will use the same apps that those people use. Unless they want to be super hard liners about it, and are willing to stop messaging people who won't use their preferred apps. The people on the other side, who almost always care a lot less about the topic, tend to look poorly on this.