The first thing is that Arsenal is a very stable team right now. And they are not dependent on any particular player. Arsenal coach Mikel Arteta has managed to create an extraordinary match strategy. As a result, every player in the team is able to perform well from his position, because of good performance as a team, Arsenal has been able to maintain consistency.
This is why the absence of an important player like Jesus is not felt in Arsenal's performance. Their performance is still stable. And this has been possible due to Arteta's excellent match strategy and the confidence of the team's players.
In this season, Arsenal have so many good factors which contribute to their success in general. They had a good preparation since the last season because their players got good experience with pressure in top four race and to maintain a position in top four. In the last season, they failed but it gave their players very valuable lessons.
It looks perfect for Arsenal because many big clubs suddenly got serious problems like Chelsea and Liverpool. They give Arsenal better chances to participate in top four and have less competitors too.
From Arsenal side, their players are performing so well and their substitution players do their jobs well to help the club getting as best results as they can when main players were suspended or injured.
I believe that Arsenal have so many converged reasons to be a winner of Premier League in this season.