Correct, though the car in question here is electric and will almost certainly use the motors to slow the car to reuse that energy. The motors should be able to stop the car even if the hydraulic brakes fail, and probably more effectively than a mechanical parking brake.

apparently some do and some don't. or they require a particular cheat code when pressing the button, idk.

the point is, you can't trust your parking brake to be an emergency brake anymore, you press a button and hope something happens

Every vehicle I've had with an electric parking brake operated the same way. Hold the park button while moving and it starts clamping the parking brake down, let off the button and it starts to release. So you can basically PWM the parking brake in an emergency.

Capitalism Progress!

If you lose your brakes you can still pull the switch and it'll apply the e-brake. If you are on the highway and don't want to slam it on, you can turn on your hazards and coast to a safe place to apply it.