I know forest fires are essential to California forests. Redwoods, for example, have seeds that wait to be burned before they will sprout. The large redwoods are big enough to survive most fires.

However, the issue has been that we suppress forest fires for years, leading to a buildup of fuel, leading to fires that are so big that they destroy the trees that normally survive them.

California has changed the way it deals with forest fires to try to prevent this... they don't try to stop ALL fires now.