They keep refusing ideas like these on the grounds of them being “not stupid” and “able to see through such attempts immediately, 100% of the time” and “do you think we’re stupid?”
If an expert can't distinguish, it has absolutely nothing to do with being "stupid" or not. So send them that, maybe.
If they are still stubborn about it, then thank them for contributing to the future funding of Scam the World With AI.
I like most am deeply unsatisfied with the archaic system though of a basically unchangeable 10-digit number granting permission for anyone to fill up my phone with messages and interrupt me with calls, and hate that I have to ever answer calls from a number I don't know.
I really would like a mutual opt-in system, where you have to pre-establish consent before it's even possible to message or call you, but it seems impossible to get there from here. We can't even get the stupid cell phone companies to strongly enforce that caller ID isn't spoofed!
How often have you met people over the phone in the past decade?
I will say that blocking all unrecognized numbers, though, is an unworkable idea. Any parent or caregiver knows that they need to be able to occasionally receive calls from a number they've never heard of before.
Not a bad idea, but not a brick wall.