Yes I remember our conversation. I mentioned that the dirt I buy is store bought, in the past I bought Miracle grow. But learned it had anti fungals added to it so I no longer use that brand. The new stuff I got was full of fungus gnats, so I can assume they did not apply anything to this new stuff to stop fungus from growing.

That being said, what grows naturally is probably not the same strains as what is sold in these products like "Great White" yes you will surely get some naturally. But I think some of these in the product are cultivated and needs to be added otherwise it would be lacking that kind of fungus.

No idea if naturally any of the fungus found in the potting soil is mycorrhizal in nature. It may just be the kind I mentioned in the beginning of this post, just growing throughout the soil itself and not bonding with the roots.

Anyways yes you are correct, in garden soil not treated with fungicides you will probably kind many beneficial bacteria and fungus. But using a product like great white probably has stuff that are not going to be found naturally.

Yes you should have..lol