Even though Arsenal's game is good, not being able to win the Premier League or the Champions League will not mean anything because the success of a club can be seen from how many titles they have won. In the previous few seasons, Arsenal's performance was good, but they had a hard time winning the title and even couldn't maintain consistency until the end of the season. This team doesn't seem to have a winning mentality and I think it's difficult to inspire a team if they don't have a high mentality and confidence.
I fully support your opinion and it is true that Arsenal in every season always fail even though the title is in front of him when he has a very thin difference in last season. The team's mentality is one of the important factors that Arsenal should have to at least get a degree in EPL to arouse self-confidence in all players to get better achievements in other competitions such as UCL. But I am not surprised if Arsenal continues like this because in my opinion Arsenal need to speculate to try to find a new coach. Because what I see the players owned by Arsenal is very good, but in terms of mentality, it is still very lacking. While the role of the coach is very important to give a great mentality to the players.
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.