Some aspects of modern warfare seem to be taking the classic idea of light infantry and dialing it up to 11. They have little armor or heavy weaponry but are such a fluid sparse target and have such a small logistical footprint that they are expensive and difficult to root out.

The modern version of this allows the same soldiers to command heavier, better weaponry via remote control that is asymmetric to their logistical footprint, enabling them to shape a battle space that would not have been possible historically.

Of course these things ebb and flow. I imagine the solution to this problem is something like autonomous drone swarms with advanced sensors that can systematically sterilize an area of any hidden soft targets. Sparsity would not be much of a defense in this case.