iOS supports this too: https://support.apple.com/en-us/HT207099

One of the features I like about it, though, is the ability to create arbitrary "pin" extensions that I can give out. I'd love for my phone number to be opt-in, worldwide.

Getting spam on a particular extension? Guess CompanyA leaked my number. Blocked.

Call screening is nice, and I actively use it, but a system that is "zero spam by default" is far more preferable than "click to block spam".