Arsenal finally gave up on getting the Newcastle United striker because their offer was rejected, or in other words, Newcastle didn't want to sell him. I think that the improvement in Isak's quality has attracted a lot of attention, but it's a shame that Arteta's target has failed.
For Eddie, of course he wants to keep Isak together because they have a big target this season to be able to compete again at the top of the standings.
So for the Gunners, of course they want to improve their front line because they need an attacker who can score lots of goals to bring them to victory in every match.
Arteta can feel that Arsenal have weakness at the striker position but he needs to find a player to replace Gabriel Jesus somewhere else, not from Newcastle United. Around the world, recent years there are very limited world class strikers and this makes competition on transfer market to purchase a top-notch striker, is very difficult.
Isak was expected to replace Ibrahimovic in Swedish national team but now he is no longer young and still can not meet this expectation because his level is far to reach Ibrahimovic's level.