Is the concept of a technological singularity valid?

Not like it does through wires, no. Electricity is involved, but only between one cell and the next, IIRC. It’s not like a wire where you apply a current at one end and instantly see it at the other - nerve impulses can take many milliseconds to travel through the body. Also, those electrical impulses are produced by chemical reactions, which limits the speed at which nerve cells can respond to a lot less than, say, a transistor.