If you wish to hide your number, then there may be several reasons behind it. The reason doesn't necessarily lie in the sinister category (yet we can't deny that it is prominent reasons.) There are some genuine scenarios where sharing your phone number is not safe (such as when you call the unknown number.) That is why iPhone has generated a technique to hide your phone number.
Source url:- https://williamsblogpoint.wordpress.com/2020/02/14/how-to-hide-your-number-during-call-on-iphone/