> no incoming phone call can ever be trusted.

They can't. And they haven't been for a while. Spoofing phone calls is simply too easy, and nothing is being done to fix that, despite the fact that it puts so many of us at risk. It's not an insurmountable problem, technologically. It is literally a lack of will and outcry from ordinary people, despite how often this fact is used to abuse so many.

Credit Card companies have known this for a long time. My credit card company will call and say "do not call back to this number, call the number on the back of your card and use this reference number".

That should absolutely be the norm at this point.