> they will definitely not switch.
How do you know? Have you asked them?
Many of my family and close friends did install a new messaging app when I asked them. How do you think WhatsApp became so popular in the first place?
Can I help you to at least try it?
Take a look at https://communick.com. You can sign up for a 14-day trial and get to invite 10 people to your plan.
I guess what I'm saying is that the network effect is just too damn strong (for me at least).