Congress already passed the TRACED Act. The FCC is moving relatively quickly in issuing government orders (as fast as a federal agency can move). It will take years for phone companies to upgrade to signing calls with level A attestation. Right now 20% of calls are signed and that includes level B attestation (we know the number is not spoofed but not who is using it) and level C (we only know the upstream phone company). If signing is implemented it will take more time to finally cut off non-signed calls. Tracing abuse takes time. Then robocallers can not pay fines and open another LLC. Hopefully this will reach an equilibrium like email where 99% of raw email traffic is spam but spam filters make it reasonable for individuals.