We have the same thought. Since Arsenal failure in the previous 2 seasons I have always said that Arsenal failure to win the EPL title was due to Arteta failure to maintain team consistency. This is indeed the biggest problem but Arteta still repeated this problem last season which should have been better because Man City last season had a tighter schedule to chase the UCL title. I had thought that maybe one way Arteta could deliver the EPL title was just by not focusing too much on chasing the UCL. And focus on rotating players in every match to maintain the players' physical and mentality so that they can maintain their performance so as not to lose points in every match.
I also think that City did not have the best season last year and this is what gave Arsenal the opportunity to follow City until the very last round. And although in the last season it seemed that Arsenal became a more stable team, I am not in a hurry to say that Arteta will completely get rid of this problem, and therefore I do not think that Arsenal can become the main competitor for City this season, at least until the first decline.
I won't agree with you for saying Manchester City didn't have a good season and that was the reason why arsenal was able to come closer to Manchester City. Last season arsenal was very tough in their performance that Manchester City was not even able to defeat arsenal in premier league games.
I think the reason why Manchester City was unable to get to the Champions league final was because they had difficult season in premier league which they needed to put more energy and focus in the Premier league. If not fir some mistakes arsenal would have won the league last season, I guess last season was arsenal best season for a very longtime because of the good performance but it was so sad that they couldn't get the tittle of the league.