About the only time an EV will need brakes is when you have the edge case of a long downhill with a fully charged, or near fully charged, battery, so that regenerative braking is not able to be used, as there is no load available to dump the energy into. Edge case, in most cases you will have a battery under 80%, which will accept charge up to a point, and which will take the majority of recovered energy. However the actual friction brakes will still get some use, even if it is minimal, so should at least get enough use to keep them rust free.