edit: Nevermind I can block non-contact calls in Do Not Disturb mode in the LG phone I'm using: https://i.imgur.com/ZcRSXlK.png Maybe iOS DnD has this too?
I guess I'm going to have to fiddle around with when the wife gets home and gather some empirical evidence.
Indeed it does, which makes it a non-solution for me. I apparently have the same desire you do - an option for voice calls to go direct to voicemail unless they are in my favorites list, without having to use the more general Do Not Disturb mode.
https://krebsonsecurity.com/2019/01/apple-phone-phishing-sca...
I use an app called Should I Answer? which has that feature. It also uses a crowd-sourced database to know what numbers to block, if you want that instead.