[grawprog]

It's not just about clearing underbrush. Ecosystems that experience frequent wildfires actually need fire for succession. Long lived plants in those ecosystems tend to be more fire resistant, they're smaller with thicker bark, shrubs and herbaceous plants will have seeds that lay dormant in the ground for years until a fire.

https://en.wikipedia.org/wiki/Fire_ecology

A lack of controlled burns leads to a buildup of dead wood and underbrush so when there eventually is a fire, it becomes the raging out of control bushfires going on in Australia right now, or in California not long ago, or in BC not long before that.

[pvaldes]

To express it grafically I would say that ecosystems need fire in the same way as humans need to suck pacifiers.