I actually emailed the FCC[1] last month and asked about/offered to try to make this available to more consumers. A realistic MVP would be an FCC-operated wrapper for Twilio's Line Type Intelligence API, so that any consumer could find the carrier responsible for any US phone number. That's not perfect, but it's a great start.
One step better would be that plus a unified contact form - basically, the process I described here, but without needing to find the carrier and then map that to a contact. The FCC already operates a robocall reporting form that goes to an FCC-operated Zendesk, but reports don't go to the responsible carrier.
Update that Mr. Egal responded and forwarded my message to the team responsible for robocall enforcement. It would be a great start if the FCC changed their reporting flow to also notify the originating carrier.
The easiest thing honestly would be someway to block all foreign numbers. right now you only have the choice of blocking any number that isn't in your contacts which really isn't an option as it blocks legitimate numbers from doctors, pharmacies, amazon, etc. I really don't need to be getting a text or call from India.
One step better would be that plus a unified contact form - basically, the process I described here, but without needing to find the carrier and then map that to a contact. The FCC already operates a robocall reporting form that goes to an FCC-operated Zendesk, but reports don't go to the responsible carrier.
The FCC did not reply.
[1]: Loyaan Egal, Bureau Chief of the Enforcement Bureau: https://www.fcc.gov/about-enforcement-bureau/loyaan-egal-2 (the person most often cited in robocall enforcement actions)