Recently my rear wheel locked up while going downhill, the lockup caused the damage in the foto(scoring in the aluminum frame by the axle) is it bad?
The bearing is of course destroyed.
Yes, it is the rear dropout (where the wheel sits against the frame.)
Photo shows the right-hand side where gears are, but both sides have the same damage.
It happened when one of the rear hub bearings exploded for some reason and the rear hub became seized, locking the rear wheel and moving the whole hub assembly up against the frame.