This is brilliant. I was today years old learning this trick. I will still maintain a whitelist for in-laws, business partners, and others (limit of 20). However, I will add this to the core family (wife, daughters, and home).
iOS also has a contacts only whitelist, you can set "Silence Unknown Callers" to On.
It's great - my only feature request would be to allow an API for app access so things like door dash, uber, amazon, etc. could be optionally allowed through.
