'Why are millennials all afraid of answering the phone or making phone calls?'
Probably because around 95-98% - and I'm not even hyperbolizing that figure - of all phone calls I have ever received in my life have been increasingly inventive robocallers trying to sell me something or trick me into thinking I owe somebody money, so my default response to a ringing phone is not 'ooh, someone wants to talk!' but 'oh good, another scam.'