STIR/SHAKEN up to this point has only been a self-certification that a telecom company has the right to use a number. What the FCC is trying to do is set up a legal obligation for the STIR/SHAKEN header to match a KYC verified identity.
If the FCC implements this, I expect a lot litigation because of the burden and legal liability this would place on telecom and VOIP companies. There are other less burdensome approaches to preventing spam that the FCC has not tried.
I am constantly amazed how few people understand that preventing spam is below the last thing the FCC is actually interested in.
First of all, the decision makers at the FCC profit from directly from spam, Christ.
Secondly, the indirect value of spam to the FCC is that it helps to justify initiatives to ruin the privacy of ordinary people via the constant push for KYC.
Just like "age verification", Flock cameras, license plate scanners, ubiquitous IoT with microphones and cameras, etc. Governments and corporations both profit from shredding every molecule of your privacy.