This might seem far-fetched, but I wonder if all the money used for reactive actions to the fires and the billions lost during those, couldn't instead heavily subsidize a goat grazing industry at large scale.

Keeping the forest clean of combustible materials is the only real preventive solution, but that's almost impossible to do by humans (besides lots of issues with depletion of soils if done incorrectly). The old way of doing that (and raise meat for human consumption) in Southern Europe, was to have goats, lots of goats, eating up all that combustible mass and transforming it into meat and "natural fertilizer".