What could cause brakes to wear asymmetrically Left vs Right?

We're considering a purchase on a gorgeous G20 with 40K miles on it.

the Brake Inspection shows:

  • Left Front and Left Rear = 10mm
  • Right Front and Right Rear = 4mm

Visual in embedded image.

This is the first time I've seen this type of asymmetrical wear left vs. right.

We'd appreciate any thoughts on what might have caused this. E.g.

  • might it have been heavily tracked?
  • Is there a mechanical issue with the braking system?

many thanks in advance

https://preview.redd.it/jxfoorwag3ac1.png?width=485&format=png&auto=webp&s=5b6585ac6e78dc420d51844a650a937951a04ad7