Lets say via packet timing analysis it doesnt matter if you run your connection through 100 relays and pass it over a string connected to a tin can halfway through, the unique flow of your packets is a signature that connects Alice to Bob without fail.
Lets say all the IX points and undersea cables are actively monitored and recorded by every industrialized superpower who then share all this info with eachother so as to have access to every stream in the world in realtime.
Lets say networks that try to obfuscate this stream get special attention.
Lets say theres a group of drugusers/pedophiles/terrorists who despite being told all of this decide to keep using these networks as if this werent a reality,
What do?
The NSA wrote, and or has taken over and provided a version of Tor specifically for the purpose of being able to spy on the people who would use it, scare people from using it, allow covert people to communicate without other governments decrypting their transmission, etc.
Tor, when used properly DOES, or DID provide a mechanism to hide source and recipient participants from edge detection. The technology already exists and is called Secure Transmission Control Protocol and was developed by the US Military for its own military Internetwork. (The US invented the Internet, BTW, and they built into the consumer edition the features of tracking, tagging and tracing).