> I'm also not sure what the correct solution is but I'm sure there's some pretty smart people out there that have some really good ideas and understand the issue with a lot of complexity
While there are certainly technical challenges and various trade-offs, those are not the main reason we're still getting buried in spam calls. My understanding is that smart people have already come up with good solutions which can be implemented at relatively low cost and which would be substantially effective - but the solutions have not been universally deployed because:
1. They generally require coordinated action between governments, standards bodies, regulators and disparate companies at different levels of the telecom ecosystem. These parties have divergent processes, goals and opinions on who should bear the costs and/or responsibilities for implementation, enforcement, etc.
2. The major U.S. telecom companies make money by transiting calls they know (or should know) are very likely spam. They don't want to give up that revenue so they find ways to not fully adopt, delay or weaken various proposals. These can include the motivated leveraging of legitimate technical issues or concerns to complicate, defer and otherwise hinder the processes in which they are involved as significant stakeholders. Many mobile phone operators now also earn revenue selling spam call blocking as a separate feature or part of more expensive plans. If the problem was substantially fixed they would lose that revenue.
3. There are various political stakeholders, industries and companies (not the off-shore, bottom-feeding spammer/scammers) which have a vested interest in keeping unsolicited calls legal. These include some of the more legit-ish forms of domestic telemarketers such as recruiters, fund-raisers, political campaigns, pollsters, market survey companies, etc. These companies have industry associations which hire lobbyists and make political donations to ensure their particular use is exempt from any regulations and that their cost of doing business doesn't go up to comply with the new system. Carving out all these exceptions and exemptions significantly complicates and/or weakens most technical solutions.
This is why I believe there is currently zero hope of any significant improvement despite the FCC issuing positive sounding announcements exactly like this one every 6 to 18 months for the last ten years. These FCC announcements rarely mention the workarounds, exemptions, appeals processes, delayed or unfunded enforcement which industry insiders already know will allow spam calls to continue with no substantial change. These announcements are merely the FCC fulfilling their political role of appearing to regulate and taking steps to mitigate the problem. Now the FCC managers who are measured on "do something about spam calls" can check that box on their KPIs. However all the various parties in the ecosystem have already taken steps to ensure whatever the FCC is announcing won't really work well or can be worked around relatively easily. For example, I'm sure most of the people behind the companies supposedly banned in this announcement (or their large offshore spammer/scammer customers) have already made other arrangements to continue operating uninterrupted. I hate that it's this way but the reality is, until the three fundamental blockers listed above change, this is all just "Regulatory Theater" much like the TSA's "Security Theater" performances.