Rrog told you, the air. ALL this stuff is airborne, Myco's too. Whom do you think was spreading Myco's around 100k years ago?Hmm... I wonder where they come from then... maybe the Ewc?
You are way, WAY, underestimating just how tough and resiliant both fungi and bacteria are and they are the first life forms.
Earthworms didn't even exist in N America till re-introduced from Europe 4-500 years ago. The last ice age wiped them out. But the fungi and bacteria were cranking rght along without them. They either went dormant till the ice melted or floated in from elsewhere.
A shovel doesn't even rate as a distraction.
Wet