Very expensive technology, and like everything else, more accuracy and faster data processing costs more money.
But the better ones are very accurate in the mouth as well as in the dental laboratory. It is past "up and coming". It is here today. Use has been growing by leaps and bounds. When used for capturing teeth and gums in the mouth, the full circle is that the dental practice has 3D printing, and CAD-CAM milling for crowns and more. Otherwise, the dentist sends data file to the lab and they take it from there. Even if dentist takes old style impressions, the lab scans it and does it digitally from there.