Many people in fact rely on WhatsApp. But that's not like they own the only road available.

If for some reason WhatsApp suddenly vanished, people would switch to the competitors, like Telegram, Messenger, Viber, etc.

There would be chaos during the change, but that's just because the change happens suddenly. If it happens slowly (if the government continues to block WhatsApp, people will rely on an alternative), then I see no harm.