How Morrowind and other open world games work has very little in common with the approaches used in R&C or Titanfall 2.

This approach has its own unique limitations. In Morrowind, you cannot instantly teleport from one side of the map to the other, in theory that would only be possible between adjacent cells. Otherwise, fast traveling would be instantaneous.

The beauty of what R&C does is that there are no limitations at all. You can almost instantly teleport between any maps the game has. No hacks or trickery beyond the brief animation concealing the 1-2 seconds it takes to shuttle the data from the SSD to VRAM. This is unique, and simply wasn’t possible on spinning rust without radically simplifying your level design and visual package to fit within the limited bandwith.