Madueke may have underperformed at Chelsea, but it's still possible that his performance will improve at Arsenal, coached by Arteta. After all, I don't think Arteta would just sign a player without knowing them and their potential, so signing Madueke from Chelsea shouldn't be considered a mistake until he proves his worth next season.
Noni Madueke's arrival at Arsenal means Arsenal have signed two players from Chelsea this July. Kepa Arrizabalaga was their previous signing, but Madueke is their latest addition so far. Madueke will likely face competition from Bokayo Saka or Reiss Nelson for a starting spot, but I'm confident Saka will remain Arteta's first-choice player, with Madueke a secondary player.
How is he going to improve if he is going to keep the bench warm most of the time for as long as Saka is fit and on form? Honestly, even before the season starts, I feel like the signing was not necessary. Arsenal's most pressing issue is getting a center forward, or even 2 of them. This is what lead to their downfall last season.
Chelsea must the happiest team in the English Premier League at the moment because at least they know where you offload players they no longer need