Bob Noel wrote:



The move to RNP is, in part, driven by the desire for increased
airspace capacity, including airspace with limited radar coverage.


No doubt about its usefulness in areas with limited, or no, radar coverage.
But, I doubt that offset tracks would do much good there. Where the terrain
environment would permit parallel tracks, the publication of parallel tracks
as separate database routes would probably be much safer than issuing
parallel tracks in a non-radar environment.