I live on the west coast of north america - the last few years following wildfires my mum heads up to the scorched mountaintops to pick morels and sells them. Big hauls, hundreds of dollars' worth of rare mushrooms growing in ruined forests.
I knew a lady who, her and her two kids, make $1500 in a weekend. Oregon Coast range, don't remember what types. It's important to remember with all mushrooms there are only a few good days a year.
They aren't really 'rare' they just can't be cultivated in captivity at a commercial scale well due to their need for a symbiotic relationship with trees as well as Morels being very picky about their fruiting triggers. I have seen people successfully 'seed' an area by making a slurry by blending molasses, water, and wild foraged morels that were subpar and letting the spores germinate with a water aerator running in the bucket and dumping the slurry in areas on their property that were favorable to Morels.
We should put more effort into learning how to farm them, as they are so highly prized.
A hundred years ago, there was enormous production of truffles (fungi with underground fruiting bodies) in Europe, but all of that production was lost when they fell out of favor. They are not the most nutritious use of the land, but lost none the less.
Some do, naturally. Otherwise, there wouldn't be so many adaptations to exploit it, thus the subject of the parent post and its linked article.
"In the wild, many trees depend on fire as a successful way to clear out the competition and release their seeds. In particular, the giant sequoia depends on fire to reproduce: the cones of the tree open after a fire releases their seeds, the fire having cleared all competing vegetation... Eucalyptus regnans or mountain ash of Australia also depends on fire but in a different fashion. They carry their seeds in capsules which can deposit at any time of the year. Being flammable, during a fire the capsules drop nearly all of their seeds and the fire consumes the eucalypt adults, but most of the seeds survive using the ash as a source of nutrients; at their rate of growth, they quickly dominate the land and a new eucalyptus forest grows."