The most annoying thing is that you can’t just message a new phone number. You have to create a contact and then add their phone number to that contact, close the contact app to go back to WhatsApp, press “+” again, search for the contact you just made, select it, then start typing. God forbid the phone number is entered wrong and you have to go back into the contact app. Meeting someone in a bar/club (outside the US), it’s a 3-4 minute process with a high error rate. WhatsApp, let me type a phone number in directly into a new message!