I definitely agree that he is a player for a 3 man midfield. For a 2 man midfield normally you need less specialist, more complete players.
Disagree that he isn't a better passer or has no vision for making a pass compared to our other players. The fact that he more often finds a target is evidence of having vision. It's not trivial to always keep the ball flowing, if it was then Barca's style would be ordinary.
Against Milan it was very clear. Bentancur missed 12 passes in 75 minutes. Arthur came on and missed 0 passes in that position, 100% accuracy.
Against Barca, Arthur with the highest passing accuracy of our midfielder, 90%. Ramsey 80%, Bentancur in 15 minutes 67%.
Not that Bentancur or Rabiot can't do great, but they are less consistent in this. Arthur on average has the most passes and the highest passing accuracy of our midfielders.
He needs to get better stamina and improve all around, but he is useful and his set of skills is not common.
It is easy to have 100% pass success when you pass it 5 yards to the guy standing next to you. It is the same reason guys like Demiral and Rugani have decent pass % despite not being good with the ball. People get far too hung up on stats. They don't show you the passes he chooses not to make, the speed of his passing, the distance, how long he has held the ball before making the pass.
He does not regularly find his target when it is not to the guy next to him. I clearly remember in his last game numerous give aways.
Having a good pass % is not a benchmark for good vision. He often does not see passes which are available that are better options that what he chooses. A few seasons ago Leon Britton of Swansea had the highest pass % in Europe, it didn't make him a top mid with good vision.
I like mids who get on the ball and keep the ball moving and don't have anything against short passing if it is quick and effective. Arthur is far too often the opposite of that. He gets the ball dallies on it and makes a slow pass that doesn't really achieve much.
He did well against Barca, as everyone did. However, I would expect him to have a higher % than Ramsey given their roles and Bentancur given the stage of the game that he played.