Arsenal can get the EPL title when Arteta is really ready to give up the UCL and focus more on winning the premier league title. But that is very unlikely and it will not be possible for Arteta to easily ignore the UCL title. Because in my opinion Arsenal do not have strong experience to win titles in the UCL or in the EPL. If Arsenal focus more on one of these competitions, I am sure they can win the title they want. And for me if Arsenal fail in the Champion League but successfully win the EPL title, it can build the mentality of Arsenal players to fight for titles in more prestigious competitions in the next season.
Failure that occurs continuously in almost every season is very bad for the team's mentality. So it would be better if Arteta started focusing on just one of them. Although I remember Arteta did it several seasons ago. Or the season before last season. At that time, Arsenal lost quickly in the UCL and they focused on the Premier League. And at that time I remember Arsenal even led the standings with a fairly large point difference. But the problem that came at that time was that Arsenal lost several players due to injury. And at that time Arsenal started to lose a lot of points and Arsenal was finally replaced by Man City at the end of the season.
But maybe this time Arsenal will be able to play better and have made quite good preparations for the second tier players. So it shouldn't be a problem for Arsenal to focus on the Premier League in the coming season.