They do not "eat fungi corpses" you absolute buffoon. Plants absorb resulting nutrients from their decomposition.
And where do those microbes, when we go far enough down, get their energy? By eating amino acids that would otherwise form into life.
I would be curious to know how easy you think abiogenesis is achieved.
I guess you could say this is the bottom of the chain as long as fetuses aren’t people so amino acids aren’t life, but that seems like a cop out at that point.
It's not a cop-out, this is just you conceding.