I think arsenal are responsible for the outcome of their present ordeal and should rather look for a possible solution, you can't possibly loose out of the title race twice in two seasons after taking the lead for a long time, I think Mikel arteta should make some changes in his team and also see how he can strengthen his defensive line up, earlier this season they looked like a side that was ready to do the unthinkable but right now they look like a ship that has lost her way on the ocean, Mikel arteta seem to be preparing a team for only the first half of the season instead of the whole season that's why the same thing keeps reoccurring over and over, that I would advocate for him to get a second eleven or engage the rotation policy so he can preserve some players for important matches.
There is no need to be pessimistic. Arsenal had a very good first half of the league, only stumbled in the last 3 games and looked like falling behind. But the points difference with the leader is only 5, a gap that can be closed very quickly. They need to add in this transfer window. Arteta also wants a bigger squad. Rotation players should be more solid. If they don't have good players to make moves when the game is stagnating, they can't unlock. It would be great if Benzema comes, but even if he doesn't, they need a good goalscorer. They don't have a player who scores 10 goals. That alone shows that they don't have a reliable goalscorer. Jesus needs to be given more time, he's just coming into his own. Ivan Toney is returning to football and has been linked with Arsenal. I'm not sure what a player who hasn't played for so long can do at Arsenal. Despite the cost, Benzema would definitely be a better option for them.