Non-EV driver here; glad I did a search making the "obvious" reply. Surprisingly, "one pedal driving mode" is a thing. Its described as opt-in with a switch or setting, so I guess there's still a brake pedal. Which means some QA techs must have test plans with "switch off, step on brake pedal" and "switch on, step on brake pedal." Or maybe "switch on, step on brake pedal" is undefined behavior and the compiler can optimize it out.
EVs always have physical brakes and pedal too in addition to regenerative braking. Regenerative braking can't come close to the braking power of disc or drum brakes especially if the battery is full.
Sportier drivers may wish to brake and accelerate simultaneously (rev matching, weight transfer tricks). Normal cars just cut fuel when braking to avoid two-foot drivers burning their brakes.