I make it simple: If my friends, customers coworkers etc. ask me if i have whatsapp - i say no, But they reach me : Via Telegram, email or sms ;-)
So i see no problem to substitute WA with Telegram. My contact list in Telegram growing, and when i show people telegram, they agree, that " it looks and feels like Whatsapp"

People use WA, bacause other do, the don't know any alternatives... But there are alternatives there. Of course Telegram is not so well-known like WA, not so open and transparent like XMPP/Jabber, not so secure like Signal... But i can live with it without thinking about my account will be banned because i have: unsupported client / unsupported os / abandoned Protocol or root... ;-)