I think email and phone spam differ, in part because there is a semi-centralized authority setup for phone calls, as the FCC and other govt organizations sort o

I think email and phone spam differ, in part because there is a semi-centralized authority setup for phone calls, as the FCC and other govt organizations sort of control it along with a small handful of real consumer phone companies (in the US that's just Verizon, ATT, T-mobile). And I think email spam is basically a non-issue for most users nowadays, it's super easy to filter and ignore emails in aggregate. Your 2FA thing is a good point, but perhaps they could be allowed to do SMS and nothing else. Or I could temporarily deactivate it. The point is, users have no control now. Tracebacks are definitely something phone companies are attempting (or claim to be able to do so). If some companies don't cooperate, ideally those calls would never complete. If they make phone calls more expensive, I consider that to be a good thing at this point.