This is true because they use cameras and camera lack depth information despite it being used with “state of the art AI”. This would not be an issue if they have any real depth based measurement system like a LiDAR.
(Serious question, I know nil about machine vision)
But having both would be best. The drawbacks of camera are additional compute being necessary for stitching and the risk of occlusions occurring due to something like adverse weather conditions. It also only offers a calculated estimation rather than a true distance measurement.
https://www.thetruthaboutcars.com/2012/03/subaru-uses-stereo...
1. videos: https://www.lensangle.com/how-do-rangefinder-cameras-work/
2. a photo or two: https://www.howtogeek.com/365801/what-is-a-rangefinder-camer...