It's insane that telephone service companies aren't getting greater scrutiny in all of this. For marginal profits they're allowed to create giant financial craters in the lives of citizens.

Why do banks have to "know their customers" and telephone providers don't?

Telephone companies are required to implement the STIR/SHAKEN protocols to authenticate phone calls. But it doesn't seem to have stopped the flood of scammers.

I have read that one problem are VOIP systems which can spoof outgoing phone numbers. It sounded like these are easy to attack. Or maybe scammers just make fake VOIP calls from overseas.