ev automotive conversion

i have been trying to find out if regenerative ev systems provide the same hold back as an ICE on a long downhill slope.

All other websites seem only to talk about efficiency and not effectiveness.
ie. its of no value to get efficiency of x% recharge if you lose control because the car is basically in neutral and relying on brakes which can glaze over and fail.

Many thanks
No, it cannot provide the same hold back as conventional brakes. Hence, you still need to apply brakes (with friction). All the regenerative braking does is converting the kinetic energy (in inertia) to electrical energy to be used in battery charging. When the kinetic energy falls, the speed also falls (K.E. = 1/2 JW^2) acting as auxiliary brakes. It could stop a vehicle if the downhill slope is few degrees slant. But generally speaking, it won't.