Apps like telegram and signal have similar capabilities but those apps just aren't on the radar of the audiences we are targeting.

For example, one of our use cases is youth sports where we've personally experienced problems with messages getting lost in group chats; parents not wanting their phone number/email or name on communication threads; coaches managing phone number lists for parents and athletes, etc. They view telegram and signal as something you use when you have something to hide - so they stick with options they don't like, text or whatsapp, because they don't have an alternative.

Telegram bot doesn't let you broadcast to a large subscriber list