Why do Computer Navigation Fixes still exist now that GPS waypoints can be used to define tracks?
From the AIM 1−1−17. Global Positioning System (GPS)


  (2) A Computer Navigation Fix (CNF) is also a point defined by a
  latitude/longitude coordinate and is required to support
  Performance−Based Navigation (PBN) operations. The GPS receiver uses
  CNFs in conjunction with waypoints to navigate from point to point.
  However, CNFs are not recognized by ATC. … CNFs that do appear on
  aeronautical charts allow pilots increased situational awareness by
  identifying points in the aircraft database route of flight with
  points on the aeronautical chart. CNFs are random five-letter
  identifiers, not pronounceable like waypoints and placed in
  parenthesis. Eventually, all CNFs will begin with the letters “CF”
  followed by three consonants (for example, CFWBG).


As an example, the glide slope intercept for an ILS that I fly shows up in the Garmin 430 as a waypoint since the GPS requires a FAF to sequence to the MAP in order to conduct an approach. But it does not show up on the chart. (Remember that an ILS doesn’t have a FAF on the chart.) I have seen them on charts, but none come to mind right now.