A tyre is worm excessively on both edges. This most likely cause of this type of tyre wear is

A tyre that is worn excessively on both edges is most likely caused by underinflation. When a tyre is underinflated, the outer edges of the tread make more contact with the road surface compared to the center, leading to increased wear on both edges. Proper tyre inflation ensures even distribution of the vehicle's weight across the tread, reducing the likelihood of uneven wear.