Visualizing Simplifications
We might picture such simplifications as paths on an N-dimensional landscape:
Complexity is measured by the distance one must travel upward.
Problem solving scope is measured by the area of the clearing.
Paths that lead to low but small canyons with steep walls (like range equations) may be easily accessible, but limited in their usefulness.
There are no absolute altimeters in this landscape, since algorithmic complexity is constrained only by the minimum path known.*
Hence wide clearings first discovered on high altitude trips (like spacetime after a trip through multiple inertial frames) may later be shown accessible by shorter paths (like the metric equation) and hence to be lower in altitude (albeit no less useful)!
* cf. Zurek, W. H., Phys. Rev. A 40 (1989) 4731-4751 or Bennett, C. H., Sci. Am. 255-11 (1987), 108-117.