In the last two seasons Arsenal have been the most serious title contenders with Manchester City, but when they are just one step away from breaking the negative trend over the last 20 years consistency is the main problem that makes them finally fail to break the dominance of Manchester City, I think in the last two seasons Arsenal have had quite good squad depth and they can minimize the occurrence of injuries to their players, But the main problem for Arsenal at the moment is that the mentality and consistency they have is not as good as that of Manchester City, besides that Arsenal still often lose momentum when they have to face crucial matches that they should be able to win, this season many other teams have improved their main squad so I think it will not be easy for Arsenal to repeat what they did in two last seasons, Besides that I think we all here would agree if Arsenal need a qualified main striker at the moment.
I agree that Arsenal has been strong team lately but they have not been consistent enough to beat Manchester City. They have good team with many players but they struggle to win important games. This is where they differ from Manchester City.
This season will be even harder for Arsenal because other teams have improved. To be best Arsenal needs to work on being consistent and having right mindset. They also need good striker to score goals. It's disappointing to see Arsenal come close but not win because of these issues. If they can fix these problems they might finally be able to challenge Manchester City and win title.