I agree. However voltage is relevant for insulation, which also affects how heat can dissipate for the wire, and might also be relevant for a failing wire, when

I agree. However voltage is relevant for insulation, which also affects how heat can dissipate for the wire, and might also be relevant for a failing wire, when higher and higher voltage can build up at the point of failure (not sure if it's a common engineering consideration outside of fuses, which are designed to fail).