It's actually not completely dead... It's just (almost) completely non-public.
You can subscribe to services to get number porting information where the interface is basically e164.arpa queries to a private nameserver over a VPN. I don't know the details, the cost was high enough that it didn't make sense for my employer to pursue it.
As someone who's been in the VoIP industry for over 20 years it makes me sad to think of what could have been if both ENUM and IPv6 were more widely adopted. For many years you could reach me via email, SIP, or Jabber with the same identifier and if there were effective support for ENUM in the USA my work phone number would have been able to connect you to any of them, directly and with G.722 HD voice long before it eventually came to modern cellular networks.
> So I had accidentally logged hundreds of thousands of phone numbers and timestamps for calls going to military bases.
That's quite a jump to conclusion right there.
Makes me wonder how many partly implemented but ignored protocols like this exist.