Arsenal have spent a lot of money in the last few seasons to build their squad but they have not been able to win any major titles and that is clearly a failure. If you look at the game graph, The Gunners have always been able to improve but mentality is a big obstacle that makes performance inconsistent. And in my opinion if this season fails again to achieve achievements then Arteta's position deserves to be evaluated and it is very possible that a change of coach is a must for the sake of the big target to be achieved.
You’re right. Arsenal have not been winning trophies but building a team to the level to be able to compete for every trophy and most especially European trophies as Arsenal have been mocked for all the time, this process takes time and I feel Arsenal are very close to achieving that level when Arteta signs a prolific striker. The defense is good, midfield is okay, just a few pieces to add up and Arsenal will be good to go.
Arsenal is not a weak team, but the mentality of keeping a long consistency till the end of the season is what they already have a problem with, and that is why after being able to perform aggressively in any competition, they later fail to achieve a trophy, although I think the team is currently okay at the moment, but who knows if they will be able to secure any trophy this season? At this point, I also think the problem may be from the manager because the players are strong and good enough to make this happen, but I think the strategy he uses is what makes them feel disappointed at the end of the season.