There are many living things in the world, most of which we don’t really care about. No one asks a tree if it wishes to be a plank of wood. No one feels bad for eating a potato, and only some would feel badly about training an ox to pull a plow. There’s no evidence sentience is a product of the number of neurons; there are creatures with many more neurons than us that are far less self-aware. Much like the circuitry of a chip, it’s not the amount of copper and silicon that makes it work, it’s how it’s arranged. The cells themselves do not suffer, they are fed and functioning and that is sufficient, no different than a bacteria. Beyond that, a neuron based processor is no more sentient than copper and sand unless we design it to mimic a living brain.