Fingers, for instance, not only have higher sensitivity, but also much higher spatial resolution due to the more dense nerve network.

I can't tell why other areas may have needed higher spatial resolution; maybe it was evolutionary important in the past, and remains today. Or maybe just adding more nerves due to a random mutation correlated with better reproductive outcomes due to a stronger signal, or higher sensitivity, so more nerves are present for no other reason.

Wait, so what you’re saying is, we can use our genitals in a pinch that could be as good as fingers for finesse?