I have my phone set to send any phone number that I haven’t called or put into contacts directly to voicemail. It’s not about being afraid to talk on the phone, but rather the proportion of useful interactions to annoying ones. 98% of the time, a call from an unknown number is going to be a scam or spam (or both!). Picking up the phone every time it rings is just a huge annoying waste of time, and anyone who is genuinely trying to get ahold of me will leave a message so I can call back.