I lent a car to someone in college who only noticed the ebrake was still on when a campus officer flagged them down to ask why the back wheel was smoking.

It's called either handbrake or parking brake and that is what it is. I think calling it "e-brake" is American thing, bit weird like calling starter motor a "railroad e-motor".

Anyways, other reasons for electric parking brake than already discussed is hill and stop light hold. Electronic brake pedal control relies on stored negative pressure on brake booster and cannot maintain pressure indefinitely, as opposed to electric parking brake which can.

> Probably bad to rely on it in an emergency given it has no abs

If the normal brakes don't work (which, admittedly, is much rarer these days), it's your last line of defense.

It's less important than it used to be, with dual redundancy required by regulation and with digital systems monitoring both braking loops. But there's still single points of failure on the brake pedal (like the pedal itself).