ArsTechnica's Jon Brodkin has a well penned recap on what attorney generals in all 50 U.S.A. states are doing about Robocalling. Honestly, not much.
In so many words, the AG's (i.e. not OGs) are basically giving the major carriers in the USA the ability to say "it's the other guys problem" and putting the blame on the "upstream provider." In other words, where the call originates, not where it terminates.
This puts more pressure on those UCaaS and VoIP providers not mentioned in the story to take more action than the guys with the deepest pockets and most subscribers. This approach is akin to "it's not me, it's everyone else" or on par with the "ostrich" -- if I bury my head in the sand it will go away.
How can this happen this way? Well the big carriers are all heavy with lobbyists, while the VoIP players and underlying carriers are not. The majors all have a heavy presence in Washington D.C, on Capitol Hill, and in the 50 states capitals too, and while they would claim otherwise, likely "cooperated" on an educational effort to get things to a point of where things are.
Yes, it's a start. Not a great one, but a start nonetheless.