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.
Arteta was not too bad to be Arsenal coach because he was able to make a change after replacing the previous coach and even in his first season as Arsenal coach he managed to present the FA Cup title. What Arsenal needs to do to build the confidence of the players because mentality is important in an effort to achieve success. If this season Arsenal fail again, the next season it will definitely be far more difficult because there are many teams that may have made changes so that it will make it difficult for Arsenal to compete. If the mentality has not been formed properly, it will be difficult for Arsenal to achieve success in any competition because they do not have more confidence.