I'm struggling to understand why this system would be offline while the FTS website is still online: https://www.ftc.gov/

Is there a technical reason for the registry to go offline, or is it an intentional casualty of the power struggle in DC?

I never signed up for it because I know this is really a method for giving telemarketers a list of good phone numbers. I hardly get any calls were people I know who signed up gets lots.

That is because these companies opened up subsidiaries in foreign countries and used the list to call people. Many calls people I know get are from spoofed numbers located in other countries.