I gather that the claims about mycorrhizal networks have been overstated or at least the evidence is limited. e.g. see this episode of Science Fictions

https://sciencefictionspod.substack.com/p/episode-91-entangl...

But even in the most conservative reading of the evidence, there is a lot of amazing ecology going on here. And the economic analogy seems apt. I buy her argument that it's worth investing a lot more to explore these interactions.

Stepping back - evolution has had a vastly greater amount of time to deal with economic & game theoretic situations than we have. Learning more about what type of strategies have survived the test of time could be very important. Especially as we are currently at the beginning of an explosive change in our own ecosystem (and I ain't talking about biodiversity or climate change...)

Without them the earth would be completely covered in layers of wood - can't have those pesky trees ruining the planet !

I suppose a climate change will interact with fungal networks in interesting ways.

IMHO basically we know very little. One thing we do know is that they are not only critical for breaking down old biomass but are 100% non-negotiable partners for many specific angiosperms. Once you lose the soil biome, those species just don't grow. Therefore when transplanting something it can be handy to bundle a sample of nearby earth at an appropriate range of depths. This can sometimes enhance germination and growth potential for difficult species by including a fungal colony... especially in difficult biomes like denuded or pool soils where a critical fungal symbiote is generally more likely.

This technique was taught to me by propagating native plant scientists here in Australia, which has a great number of unique plant species owing to its historic isolation and consequent evolutionary independence.