> Friction braking is always needed to make a full stop.

In my EV6, I have a paddle on the left of my steering wheel that I use (almost) exclusively for braking. It 100% only uses regenerative braking, and I can definitely tell the difference, as its stops are much more subtle than when using the brake pedal for stopping (even when coming to a stop super gently).

More evidence that it doesn't use friction brakes: when I use the left paddle to brake, the car will sometimes edge forward (just an inch or two). With friction braking, this obviously never happens.