Our Buick Enclave has both the backup camera and the radar sensors. The sensors work really well at sensing items behind the car/SUV/crossover/minivan without sliding doors.
Ours will pick up most squared off curbs.
Will pick up walls/fencing to the side as I approach it (even if I would not hit them if I continued to back up straight.
I have a carport on the side of the house, 3" square tubing, covered with tin. The sensors will notify me of the carport while I'm backing under it, so it is picking up a 3" wide piece of steel that is ~2' to the side of it as it approaches.
Now a backup camera is a cheap addition to your existing vehicle, and can help in many situations, but I find that I don't actually look at the camera display very much (unless I'm hooking to a trailer or backing up close to something, or when the sensors alert me of something).
For what it's worth. I almost always park farther out in the parking spaces, usually pull through or on the end, or back in. I look and hope for nobody crammed next to me, makes it easier to load kids in the car seats.
