[ghaff]

The 90% use case is that someone wants to make it quite hard for an Internet rando (or maybe their employer) to connect them to their "true name" and, by extension, all the other data connected to their true name--likely including their address among other things, especially if their name is uncommon or other data is already known. This is pretty easy in the US.

Making it so no one can make the connection is much harder (as in close to impossible) and probably illegal in many cases especially if money is changing hands.