We've had a family group going for quite some time. It's mainly used to organize gatherings, sharing photos/videos and sometimes discussing issues. It started on Wechat while I was living in China, then we moved over to Facebook messenger about 4 years ago. I ended up leaving Facebook and let my wife deal with connecting socially.
I thought I'd try and get them to move over to signal by letting them know that Facebook is selling their data to third parties. They probably knew anyway, but all the convenience and network effects are hard to shake off. To my surprise they agreed and now we have our group in an ideal territory.
I feel like Signal have hit a sweet spot as it's quite noob friendly and has all the same features as Whatsapp/Messenger.
Anyway, just thought I'd share this small win!