With iOS 13, Apple will be giving users the option to automatically block calls from unknown numbers and send them straight to voicemail. This means that in the event you receive a phone call from a number you don’t know, it will be automatically sent to voicemail and you don’t even need to do anything on your end.
It has been reported that the feature will actually be capable of digging through your contacts and emails to look for the number that is calling you, meaning that it will do its best to try and identify it before it blocks it. For example, sometimes you might not have saved the number of a restaurant that you’ve made a booking with, and then the restaurant tries to call you back to confirm the reservation.
So if it is in your email, then iOS 13 will be able to detect that it is a legit call and will let it through. While it might be useful for personal use, we imagine that for people doing business and might receive a ton of calls from numbers they don’t know, it might be considerably less useful.