That's a fallacy that is getting out of control.
He has more successful dribbles and key passes than Walker. More crosses per game than R.Peirera and Walker. The best ball control % out of Walker, R.Peirera and Aurier. Despite being 4-7 years younger than all of them. He's poor offensively when you compare him to Alex-Arnold, which is an unfair comparison.
Yes, we purchased a more defensive full back. But he's not as terrible going forward as most people claim. Our whole team struggles in the final third because of how we are set up to break them down, too slow. AWB is given the ball too late, once he has become stationary and the passes are telegraphed. He often finds himself given the ball with 2 men to beat (e.g. against Burnley - and he still was trying to make things happen) with little movement in and around the box.
Compare his attacking play in this video to what you see now.
The problem is our tactics, not the player.