New hazard: Cars without reversing sensors

I’ve grown very used to the reassurance that comes from having proximity sensors on the rear bumper of my car. They allow me to drive in reverse safely without worrying about hitting out of sight obstacles. It’s a great safety enhancement.
 
The trouble comes when I then have to drive a different car that doesn’t have reverse sensors. That’s when I realise how dependent I have become on the reassuring beep of those sensors. Without them I find myself unable to confidently judge distances behind me. And I’m far less likely to notice some of the obstacles in my reversing path. In fact, I’d go so far as to say that I think reversing sensors (or rather the lack of them in some vehicles) have actually made me a less safe driver. While my chances of hitting an obstacle with the sensors have gone down, the chances of my hitting something without the sensors have risen. I guess the same could be argued about warning beeps that remind you to put on your seat belt. If you get in car without the warning aren’t peope at risk of forgetting and putting themselves at risk?
 
Surely a technology crutch on which we become so dependent cannot be a good thing. Or is it?