From a brief look at the article it appears that this works by your phone asking the device purportedly belonging to the caller if they did in fact make the call. So it's authentication at the device level, not at the network level.
Unfortunately it only works when both the recipient of the call and the purported originator of the call both have properly configured Android phones. It would be nice if Google could have implemented this in such a way that it would work with a combination of both Android and iPhone devices, and didn't rely on a handful of Google-specific apps. If they could have done that it would likely have worked on well over 90% of mobile-to-mobile calls with little to no setup.
This, and this:
As usual, some of the new features are limited to specific devices,
and others require using Google’s apps. But if you don’t mind the latter, you can get
automated protection from the growing threat of deepfake phone scams.
Pretty much tells me that it won't be a thing for me, at least.
I'm a bit flummoxed to figure out who, exactly, it's for, since I doubt it will work with Apple phones (the article doesn't specify, but I doubt Apple will get on board with anything Google).
And since it seems a huge share, if not a majority, of people in the US use Apple phones, it's kind of pointless.
Besides the whole "others require using Google's apps" thing I highlighted screams "NO FUCKING WAY!" to me. I know people routinely run around with wifi or data turned on, but I don't. My phone lasts 18 hours if I have all the devices enabled people seem to have enabled. If I turn off everything, it lasts 4 days and is recharged at 20%.
Since my phone is a communications device, and I'm able to parse my calls by who I hear, rather than what the caller ID says (because I have people I know who share each others phones), and I don't answer calls from numbers I don't recognize, my being scammed is going to be a mountain too high for most scammers to climb compared to easier targets.
I get that Google wants to be all things to all people to get all the datas, but I'm not going to climb on that bandwagon.