Strikers are coached to shoot across the goalkeeper rather than back towards the side they came from. The instruction survives because it exploits how a keeper moves, not because the far corner is somehow bigger.
A keeper sets his feet before the shot arrives
Goalkeepers do not react from a standstill. They take small adjusting steps as the attacker closes, and those steps commit weight to one side of the body.
The near post is the side the keeper is already shading, because it is the shorter distance and the one he can be blamed for conceding at.
A shot travelling across him asks him to unweight the loaded leg, push in the opposite direction, and cover more ground in less time. That sequence is slow.
The angle keeps the ball on target longer
A cross-goal shot travels diagonally through the goal mouth rather than into a single spot. It stays inside the frame for a longer portion of its flight.
That means an imperfect strike still finds a corner. A near-post shot that drifts two feet wide of its target hits the side netting or the post.
Margin for error is what separates a finish that scores from one that looks fine on the training ground and misses in a match.
Rebounds fall to attackers rather than defenders
Shots the keeper does reach across his body are rarely held. The hands are extended, the wrist is weak in that position, and the ball is pushed rather than caught.
Those parries travel forward and to the far side, which is where the second striker and the arriving winger are running.
A near-post shot that is saved tends to rebound back towards the defenders who were tracking the original run, so the possession is lost.
Defenders are pointed the wrong way
The recovering centre-back sprinting back at an angle is trying to block the line between the ball and the near post, because that is the shortest threat.
Opening the body to shoot across takes the ball outside that blocking line entirely. The defender's momentum carries him past the shot rather than into it.
This is why the finish is taught alongside a slight touch away from the covering foot rather than as a shooting action on its own.
The technique that makes it repeatable
The shot is struck with the inside of the foot or the instep with the ankle locked, and the hips open towards the far post before contact.
Strikers who miss this finish usually rotate the hips after striking rather than before, which drags the contact across the ball and slices it wide.
Getting the standing foot planted pointing at the target solves most of it, because the hips follow the standing foot almost automatically.