Android does a much better job at this, and it baffles me why Apple doesn't. I get 5-10 spam calls every day on my iPhone, many of them early in the morning (I used to live on the east coast and am now on the west coast).

On my wife's phone, most spam calls are auto detected as "Spam Likely" and you can report new numbers as spam, which I presume Google uses to update its database of spam callers.