This is why I am sure Saka returning won't matter much. They didn't do terrible without Saka, so they saw that they do not need him all that much, sure it's cool to have him, but not like they were losing games all the time when he was out.
Plus, Liverpool is doing awesome right now, and Salah is doing amazing as well, so that means as long as Liverpool keeps doing this great, we are not going to see Arsenal win, no matter who they have. Arsenals fate is not based on what Arsenal does, they can win all the games, their fate depends on Liverpool and how they do, if they do well then we are not going to see Arsenal catch up. This is why no matter if Saka returns or not, we are not going to end up seeing Arsenal win, as long as Liverpool stays great.
Well, Arsenal is still solid even without Saka. It's just that if Saka returns to playing after fully recovering, I think Arsenal will be even better in attack. We know how Saka always increases opportunities for Arsenal to score more goals. He is good at making good assists which are always easy for his teammates to use. I personally see that Saka's presence will have a slight impact. But if he returns to the team and plays, we cannot immediately have high hopes for Saka because usually players who have just recovered from injury always have to re-adapt their bodies. And at the start he might not play as well as before he was injured. so yeah we can't have too high hopes in this regard. And fortunately Arsenal have continued to play well so far even without Saka. Arteta can always be relied on in this matter. But the competition with Liverpool will still be difficult. because even though Arsenal plays with their full strength, if Liverpool also plays with their full strength then it is quite clear that Liverpool will still win.