Because they are necessarily going to be treading the same ground, facing the same landscape, wrestling with the same problems. More or less.
One can wring some variation into the matter, making it less rather than more the same; one should wring as much variation as is possible, just to help keep the audience awake. Especially useful would be the pursued setting traps for the pursuer. But there's a limit to that. Particularly if they are passing through a landscape with perils of its own.
Juggling points of view can be interesting, especially when there are questions about survival when you omit one side or the other for the sake of avoiding monotony.