A scan path is recommended by intraoral scanner manufacturers as they have concluded that it allows for increased accuracy.  The result being a better fitting and more accurate restoration.
Study : 

As a dental lab, we have had situations where dentists have sent scans and the restorations manufactured and received were deemed inaccurate and required adjustment either on the occlusal or interproximal area.

Some intraoral scanners have the capability of playing a video showing exactly how the scanner captured the data. This is extremely helpful to the dental lab as they can see if the scans were gathered correctly to allow for the most accurate  restoration. If not, this would explain the need for adjustments.

SCAN PATH for Omnicam: 

SCAN PATH for 3Shape Trios:

To try either an Omnicam or a 3Shape Wireless Trios, contact the lab at 250-861-3333.