This may be true at first glance, but if you try to incorporate more advanced EV features, and in particular, regenerative braking, you very quickly do need to

This may be true at first glance, but if you try to incorporate more advanced EV features, and in particular, regenerative braking, you very quickly do need to care about maximum charge/discharge rates. Your brakes dissipate a great deal of energy very quickly; to resorb that back into usable potential is something that supercaps are exceptionally good at facilitating. That being said, in this case, you're likely best off using a supercap buffer between your batteries and the wheels, but that makes your power management and delivery systems substantially more complicated.