This is the thing. WhatsApp works really well. And so did Facebook groups. I think once communities are established they stay where they are. So anything new is for new usecases. Trying to get people to migrate isn't the answer. It's about new solutions or habits solving specific purposes. For me it's a lot to do with the fact that each chat itself in whatsapp isn't threaded. You can create communities but that's not right for informal stuff and then I can create separate groups but then it gets confusing. So actually you need topic based chat. Ability to create new topics in the same groups. Basically slack or discord for family and friends.