If we're going to be picky, also the idea that only neurons are relevant isn't right; if you replaced each neuron with a neuron-analog (a chip or a neuron-emulation-in-software or something else) but didn't also replace the non-neuron parts of the cognitive system that mediate neuronal function, you wouldn't have a working cognitive system.
But this is a minor quibble; you could replace "neuron" with "cell" or some similar word to steelman your point.