I have a convenient heuristic which I imagine is quite common. I have a cell phone with an area code from where I purchased it, but I have since moved, so all my local calls come from a different area code.
Calls from my area code of residence are almost never spam, while calls from any other area code, and especially my phone's area code, are almost always spam.
Google does have a bunch of features for screening spam calls.
It can identify scammers' numbers (based on user reports). And the phone app will label the call as suspected spam.
There is also a setting to outright block incoming calls from numbers labeled as spammers.
Then there is call screening. The google bot will answer the call and ask questions that you select (like "who are you and why are you calling?"). You get a real time voice transcription of the answer so that you can decide to pick up if needed. But it's handy for spammers because they usually just hang up (or you get some half-transcripted text of a robocall message that was talking over the Google bot).
It doesn't solve the problem completely but it does help.
I believe both Android and iOS support SHAKEN/STIR, as long as your carrier supports it. On my phone, at least, I see Caller IDs tagged with "likely spam" if a check fails.
Samsung has their own proprietary thing i think [0].
But it is great, when someone calls and i don't have them in my address book they show me the name of them, for example the name of the doctor offices, companies etc. As you can see in the demo carousel on their page, it shows "SMART" next to it, which emphazises that this isn't a number in your contacts but fetched from the internet.
Or if they are likely spam, my whole display is red and i can immediately hang up.
Both Google Fi and T Mobile used to show up likely spam calls regularly and accurately, but sadly the only network with decent coverage where I live is AT&T, which does exactly as good a job of this as you’d expect AT&T to do.
I wonder if this is a rollout thing -- I had AT&T for years, and towards the end (about a year ago) I began receiving spam notices. But I was in one of their "primary" markets, so it's possible they rolled it out first here.
iOS will show a small checkmark near the phone number on incoming calls in the recent call list. Which is great AFTER the fact. I have not seen a way to identify signed callers in the actual “ringing” screen.
Our phone provider has a free service, Call Control, that’s completely eliminated scam calls. Callers get an automated message asking them to enter a random number. If they enter it correctly, my phone rings as usual. This system foils automated calling services, at least for now.
Most "legitimate" robocalls from a school or doctor's office are better off as SMS. Does an appointment reminder really need my immediate undivided attention? If it's not worth having an employee manually make the call it's probably not worth my time to answer.
Google had a perfect solution for this, Google Voice (formerly Grand Central). This amazing product was languishing for years due to the lack of attention on Google side. They don't let it die, but it doesn't look like they let it live, either. Shame, could be a total game changer.
Problem is that it seems every online site now wants your cell phone number as a sort of captcha these days. And they’ll either explicitly prohibit you or shadow ban you if you use a voip number, making google voice unusable for this use case. So… I guess a burner phone for everyone? So frustrating.
This is the last time you'll find me praise Google but the "Screen Call" button has been a godsend for me, I haven't had to talk to a scammer in years at this point. Nobody makes it past the first couple of words.
