Another solution, one not yet adopted by the Forest Service, is an approach taken by the Federal Emergency Management Agency with regard those who live in the most flood-prone areas. After flooding one too many times, FEMA essentially forces homeowners to sell their houses at market value to FEMA. FEMA then promptly tears them down and marks the area as uninsurable. This might appear to be a waste of money, but in the long run it saves FEMA money, and potentially saves lives. Texas and some other states take even more drastic measures with coastal properties. A house is condemned once the coast line has eroded to the point that it is closer than some minimal distance of the house.

We can't build such robots, yet
The terrain where forests grow is not exactly suitable to robots. Much of the forested land in the contiguous US is mountainous. What isn't mountainous is dotted with bogs, swamps, and lakes. The weather is often rather nasty. An autonomous robot that could navigate and survive through such terrain is far in the future. Adding the ability to clean up terrain is even further in the future.

Aggressive fire suppression requires clearing out shrubs such as chaparral, which is rather tough stuff, dead and down trees that can be several meters in diameter, and small to medium sized non-canopy trees whose trunk can be up to a meter or so in diameter. This is not the job for little goat-sized robots. This is a job for an industrial-sized robot, and ED-209 won't cut it.