Again mate I see more than goals and assists. There aren't a ton of goals in football so going just off of them will cause you to miss things. That means getting into positions to score is very important as only constantly getting to those spots, and getting the ball there, will create goals. When you are playing as sporadically as he is the end product will sometimes not come, but he is still doing the other part of it, and he did it here, to suggest if he actually did play a lot it would come around.
None of our other players do those things at a high level.
Also in his whole career he has played like 1800 top flight minutes between here and Germany and has 6 goals and 5 assists, which isn't bad.
For comparison Bernard has 4 and 5 in 3000 minutes, Walcott has 9 and 7 with us in 4200 minutes and Bolasie had 2 and 4 in 1800 minutes. That's all in the league btw. Cup and Europe gets weird with quality of opponent considerations.