Sonoma County, CA here. My father worked in a State role allied with Cal-Fire (formerly Cal Dept. of Forestry) and he directly assisted with permitting and monitoring of prescribed burns.

His anecdotal take (which is not mentioned in the article) was that in the 90s and early 2000s, prescribed burns were very common (even as a kid i remember this). However, as more and more individuals started moving into the County from other areas, the number of complaints about the smoke from prescribed burns rose and the permit issuing process became more fraught with environmental reviews (air quality impact specifically) & red-tape.

I am 100% convinced that the lack of prescribed burns is the issue up here in Nor-Cal - they are rare compared to what I remember as a kid (several per month).