Well, to be honest I really enjoy having audio conversations on Whatsapp. Of course I understand that most people feel afraid to give their personal number phones 'cuase It could be a faker, right? But I'm not talking about just having conversations for nothing. I'm saying you can practice the language you're learning and help others at the same time.
Why audio conversations? That's easy. Because that's kind of a natural conversation. When you just type your ideas you have extra time to think, but when recording your voice you can't in some way...
Somtimes, it has nothing to do with "be afraid of" anything.
It is just about laziness :P