I have no idea what car you’re driving or what safety features it has.. but more importantly, your response to a crash caused by your own carelessness is to be morally indignant… towards your car?

Depends on your car. Some cars only activate these systems after a certain speed. Even then you can still overpower the system.

In cars with parking sensors, it would likely have beeped at you aggressively unless you disabled that.

It doesn't auto-brake but does do a good job of avoiding such impacts by alerting to objects nearby you might not see, including cross-traffic detection when backing out of parking spaces.

The level of automation in cars today is designed to _assist_ the driver, not replace the driver or absolve them of responsibility for their vehicle.